There are many words that can be used to describe Glee: unconventional, ridiculous, over-the-top, meta beyond belief, and, yes, star-studded. Ryan Murphy’s musical-comedy hit FOX like a hurricane (sorry, Floridians), and had an almost immediate cultural impact. Love it or hate it, the show was a force to be reckoned with, ratings-wise. Even when it began to completely fall apart, it still managed to be the hot kind of mess, and the network wasn’t keen to part with it.

Due to its sky-rocket into television popularity, guest stars quickly became very easy to come by. In between the portmanteaus defining teenage romance at William McKinley High School and the musical numbers both extravagant and slightly less so, big names began to appear for a few episodes at a time, making their way from Broadway, reality TV, network news, and even their own recording studios. Please note that these are just the celebs who appeared in just one or two episodes, because if we were to include those that had actual arcs, this list would never end. Let’s take a look at 15 Glee Celebrity Guest Appearances You Forgot About.

18. Tyra Banks

After the first three seasons, Glee struggled quite a bit. New characters were brought in, old ones were shuffled out (and back in), and the plot jumped constantly back and forth from Lima, Ohio and NYC. Seasons four and five were combined into one school year so that the seniors (read: remaining original members) could stick around a bit longer, and the dynamics were hard to work out.

Sam and Blaine, two of the aforementioned seniors, go to visit the New Directions graduates living in NYC, in order to plan their own hopeful futures in the city. Not the brightest bulb, Sam admits that he wants to be a male model – likely because it’s the only segment of entertainment not yet explored on the show. After a photoshoot, he has an interview with Bichette, the head of her own self-titled modeling agency. She spits some truth game at Sam because yeah, he’s attractive, but unlike the special snowflake Mr. Schuster told him he was, he’s actually just one of millions. Tyra plays model-turned-exec to a T… though considering her background, how could she not?

17. Jackée

Some of the troubles of the fifth season can be chalked up to the fact that main cast member Cory Monteith, who played Finn Hudson, passed away unexpectedly before shooting began. As an integral part of the show, Finn had recently become co-director of the New Directions, and so a lot of rewriting was said to have taken place before the season could even begin shooting, let alone air. In an attempt to work in (but not focus on) the death of a major character, Finn’s mom and stepdad accompany the Glee club when they head to Los Angeles for Nationals.

Though a guest star can pop up at almost any moment in Glee, they’re most frequently seen as show choir judges at the various competitions the New Directions perform at. This one was no different, as Emmy-winning actress Jackée was one of the judges this time around, along with Academy Award winning deaf actress Marlee Matlin, and Johanna Rohrback, the inventor of “Prancercise.” The group performed a set list of Finn’s favorite songs, and came in second place to new competitor Throat Explosion, led by Pitch Perfect star Skylar Astin as Jean-Baptiste. Yes, the end of the series was jam-packed with cameos.

16. James Lipton

Before he graduated, joined the military, was discharged, decided to become a teacher, and then died, Finn struggled to find his path (clearly). As his senior year was coming to a close, he decided he wanted to become an actor and, with no known acting experience and no performance background aside from Glee club, he auditioned for Inside the Actor’s Studio. At his audition, we briefly see James Lipton himself, telling Finn that if he’s accepted, it would be a very rare case.

For some reason, this didn’t deter the athlete, who was confident that he had earned a spot. Unsurprisingly to everyone (but him), he didn’t get in, which he learned at the same time that Kurt found out he was rejected from make-believe performing arts school NYADA, while Rachel had been accepted there. Finn then felt pulled to do right by his father, who was dishonorably discharged from the Army, and enlist himself. This lead to the end of “Finchel,” who never recovered after he broke off their engagement and insisted Rachel go to New York on her own.

15. Gloria Estefan

The arc of Santana Lopez is one of the most interesting of the show. She starts off as Quinn Fabray’s sidekick, quickly revealing herself to be the mean girl. She’s cutthroat and honest, and though clearly talented, doesn’t make the New Directions a priority right away, often putting the Cheerios and popularity first. Her soft side seems to come out only when she’s around her best friend, Brittany. It soon becomes apparent that the two are more than just friends, and Santana eventually comes out of the closet, going on to date Brittany after she and Artie call it quits.

We see Santana come out to her Abuela (played by Ivonne Coll), and things don’t go well. Fortunately, despite growing up in the “bad neighborhood” of Lima Heights, Santana has a great support system at home in  her parents. In season three’s finale, Grammy award winner Gloria Estefan portrays Maribel Lopez, first eating dinner with her daughter and girlfriend, while encouraging Santana to go to college on the cheer scholarship she was awarded. Later, Maribel approaches Santana and tells her to follow her dreams to New York City, handing her an envelope of money she had saved over the years. And Maribel shows up once again in season six, singing a number on stage at her daughter’s wedding.

14. Ricky Martin

Glee could be so ridiculous that, around the middle of the second season, it began to address some of its own inconsistencies. One such matter is that Will pays the bills as a Spanish teacher, but we almost never hear him speaking Spanish, or know of any Latino background he might have. In the season three episode “The Spanish Teacher,” Principal Figgins finally calls him out on this and sends him to night school, where he meets David Martinez, played by Ricky Martin.

Mr. Martinez comes to perform for the New Directions (because in this world, all teachers have musical talent), and shows off his spicy moves. In addition to his lack of knowledge surrounding the language, it turns out that Will knows nothing beyond stereotypes of Hispanic culture, and fortunately, Martinez and Santana are there to call him out on it. In the end, Schuster decides to try teaching history, leaving a vacancy for a Spanish teacher to be taken by David. Unfortunately, as with most shows, we never see Ricky on Glee again, and have no idea how long he remained employed at McKinley.

13. Victor Garber

By only the third episode of Glee, Will is already tired of the New Directions. Well, not really, but he does form Acafellas, an all-male a capella group, in order to help him gain the confidence he needs to be a dad. The seed for this idea is planted by his father, played by Victor Garber, who admits that he never had the guts to apply to law school, settling for a job in insurance to pay the bills for his family.

So Will sees his father’s regret, forms the group with football coach Ken, his wife Terri’s coworker Howard, and thumb-less woodshop teacher Henri. Eventually, Henri and Howard drop out, and determined not to lose his newfound confidence-booster, Mr. Schuster brings in Finn and Puck, the latter of whom had not yet joined the New Directions at this time. In the end, Will decides to end the group and go back to teaching, but it turns out that by pursing his dream, he inspired his father to finally enroll in law school. Josh Groban also makes a cameo appearance in this episode as himself, a role he reprises in the season finale.

12. Katie Couric

While Sue’s main mission is to take down the Glee club, her ruthless attitude occasionally backfires onto her own Cheerios. Poised to once again win a national championship with an over-the-top Katy Perry inspired number, Sue takes things one step further, purchasing a cannon and insisting that Brittany be shot out of it during competition. Figgins tells her she can’t do that, and in a fit of rage, she has the event moved to the same night as the football championship, forcing Brittany, Santana, and Quinn to choose between the Cheerios and Glee club.

Though they initially choose to remain cheerleaders, Finn reminds them that Sue is horrible to them, and that the New Directions will always accept them. They switch their allegiance, and the Cheerios go on to lose without their star athletes. Katie Couric then interviews Sue, calling her “Loser of the Year,” and telling her that all of her Cheerios budget has gone to the Glee club. In other words, Sue hits her lowest low (to that point), in as unbelievable a fashion as only Glee can deliver.

11. Matt Bomer

In season three, Kurt’s boyfriend Blaine transfers from Dalton Academy to attend McKinley and join the New Directions. While this was probably not the best choice given that it was basically the Finn and Rachel show most of the time, Blaine excels just the same, getting solos in Glee and even starring in the school’s production of West Side Story as Tony.

We soon discover, however, that there’s a thorn in Blaine’s side: His equally talented and shockingly handsome brother, Cooper Anderson. Played by Matt Bomer, Cooper shows up for a visit and is immediately recognized from a series of popular credit report commercials he had done. He swoops in and gives the Glee kids plenty of show biz advice, but Blaine calls his bluff when his elder brother uses him as a bad example. By the end of the episode, the two reconcile, and do a heartfelt duet of “Somebody That I Used to Know.”

10. Lindsay Lohan and Perez Hilton

The New Directions made it to Nationals for the second time in season three, but this time, they were prepared. With Sue on their side and the power of now-defunct girl group The Troubletones, the ragtag team actually seemed to stand a chance (despite the fact that they were competing against legit performing arts high schools from across the US). But let’s be real: With last minute food poisoning, screaming matches, and pep talks from Finn, it was really just like every other competition.

Also just like the Sectionals, Regionals, and Nationals of the past? A judging panel of mid-level celebs. Lindsay Lohan, former child star and frequent hot mess, praises the McKinley kids, because like her, they were attempting to stage a comeback. Celebrity blogger Perez Hilton, on the other hand, made his trademark nasty comments about the group. The two seemed a bit contentious towards each other, but simultaneously balked when they learned from the other judge that the competition wasn’t televised. After all, everything comes back to personal gain in show biz.

8. and 9. Barry Bostwick and Meat Loaf

After their season one finale kiss, it seemed inevitable that Will and guidance counselor Emma Pillsbury would get together. Of course, this is a TV show, where the OTPs must be kept apart as long as possible in order to keep the appeal going. Will learns in the fifth episode of season two that Emma’s new boyfriend, Carl (played by John Stamos) has opened her up to the world of theater – specifically The Rocky Horror Show. So Will attempts to use the musical (and Glee club) to win her over.

Rocky Horror is, as those who’ve seen it know, a bit too adult for a high school stage. Sue is approached by Meat Loaf and Barry Bostwick, playing the station managers at the news network where she does a weekly segment. They convince her to use the Glee club production of Rocky Horror to scare the residents of Lima, and promise her she’ll be a contender for a local Emmy if she does so. Not coincidentally, Meat Loaf and Bostwick are known for their respective roles as Eddie and Brad in the film adaptation of the musical, The Rocky Horror Picture Show.

6. and 7. Michael Bolton and Geraldo Rivera

Throughout the series, cheer coach Sue Sylvester reveals various sides to herself. She is, when it comes down to it, a mean, manipulative woman, but she has been hardened by a life with unloving, absentee parents, and a sister with Down’s Syndrome whom she never felt was treated right by society. Occasionally, glimpses of Sue’s humanity come out, but she always reverts back to her rude, angry self.

A few times throughout the series, someone succeeds at tearing the Cheerios coach down, but none more so than the final time. In the sixth season, Sue, having gained notoriety in various forms over the years, is invited by Geraldo Rivera (as himself) for an interview, where he proceeds to reveal some of the many lies she has told throughout the years. One of the most prominent of her tall tales is that Michael Bolton is the father of her daughter, Robin. Bolton himself is shown disputing this, forcing Sue to concede. As the episode title, “The Rise and Fall of Sue Sylvester” indicates, we finally see the frequent tormentor brought to justice just as the series begins to wrap up.

4. and 5. Jeff Goldblum and Brian Stokes Mitchell

One of the first things we learn about Rachel Berry is that she, in her words, has “two gay dads,” – comically explaining that while one is of color and one is white, they don’t know which is her biological father. The Misters Berry are mentioned a number of times, specifically when Rachel meets her birth mother (played by Idina Menzel), but we don’t see them on the screen until season three, when they pretend to support the teenage engagement of Rachel and Finn while secretly plotting to end it.

Hiram Berry, played by Jurassic Park and Independence Day actor Jeff Goldblum, is the more dramatic of the two (though, as evidenced by Rachel, both are clearly theatrically talented), frustrated with his partner when things go wrong in their plan, and declaring that he would fake an epileptic seizure to stop Finchel’s wedding. We don’t see him again on screen after his two appearances that season, but LeRoy Berry, played by Tony winner Brian Stokes Mitchell, shows up in the season six premiere, where he tells Rachel that he and Hiram are getting divorced and selling her childhood home…after she just failed in Hollywood. Talk about kicking her when she’s down.

3. Neil Patrick Harris

The theme of the first season of Glee was basically “this program is going to get cut, and we have to stop it.” Of the many naysayers Mr. Schuster met along the way, one of the most notable threats was that of Bryan Ryan, played by Neil Patrick Harris. In an episode directed by Joss Whedon (yes, really), Ryan comes to McKinley as a former Glee club mate of Will’s who has since recovered from his show choir “addiction,” and vows to use his school board member position to take down the New Directions and their dreams of stardom. Will quickly realizes that Bryan is simply disappointed that he didn’t make it on Broadway, and after engaging him in a duet of Billy Joel’s “Piano Man,” he convinces his old rival to audition with him for a community theater production of Les Mis.

At the tryouts, Ryan steals Will’s song, and the two audition together with a powerful rendition of Aerosmith’s “Dream On.” While Matthew Morrison is indeed very talented, it’s hard to deny the triple threat that is NPH, which is why it’s a bit surprising that Schuster scores the role of Jean Valjean. But, as often happens to Will, Sue foils him, and he ends up giving the part to Bryan in order to save the Glee club.

2. Olivia Newton-John

Despite her tough outer shell, season one episode “Bad Reputation” finally shows the sensitive side of Sue Sylvester. After a homemade music video of her performing Olivia Newton-John’s “Physical” is leaked onto the internet by the Glee kids she finally gets a taste of her own medicine, as kids and teachers alike (led by Molly Shannon in her own cameo) taunt her, and she vows to take down whomever exposed her.

But there’s a silver lining: The video goes viral, and Newton-John herself sees it and contacts Sue. Olivia admits that, while the song was a chart-topper, the video wasn’t great, so she and Sue team up and remake it. The result is hilarious: The two women wear powder blue track suits (which Sue likely already owned) as they walk around and ogle muscular men working out in red wrestling singlets. A few episodes later, Newton-John shows up as one the judges at Regionals, along with Josh Groban in his second (and final) appearance.

1. Britney Spears

The pop princess of the early aughts shows up as herself in the second episode of season two. After the show’s very successful first season tribute to Madonna, episodes featuring the songs of one performer or a particular group became a frequent trend throughout its run. In this episode, dentist Carl comes in teach the Glee club kids about dental health, which results in a number of hallucinogenic-induced fantasies.

Brittany, who up until this point was the relatively silent sidekick of fellow Cheerios Quinn and Santana, reveals a couple things herself in this episode: First, that she’s not just ditzy – she’s intellectually challenged, and doesn’t know how to brush her teeth. She also confesses to the New Directions that her full name is Brittany S. Pierce and, due to the similarities in pronunciation, she feels that she lives in Britney Spears’ shadow, and doesn’t like her.

That all changes when she’s put under anesthesia by Carl, and she has a dream where she dances to Britney’s “I’m a Slave 4 U,” taking on many of Spears’ most popular moves and looks. She goes back for more fillings with Santana in tow, and the two perform Spears’ duet with Madonna “Me Against the Music,” where Britney herself has a line at the end. Spears also makes an appearance as the teacher in Rachel’s reenactment of the “…Baby One More Time” video, and she shows up as a Cheerio during Artie’s “Stronger” fantasy.