30 Rock was an NBC satirical sitcom that aired for seven seasons before coming to an end on January 31, 2013. The series was created by comedic actress and producer Tina Fey, and was loosely based on her experience as a head writer on SNL. She starred in the show as Liz Lemon, the head writer of NBC comedy sketch series TGS, as she works in a studio in 30 Rockefeller Plaza alongside Tracy Morgan, Jane Krakowski, Jack McBrayer, Scott Adsit, Judah Friedlander, and Alec Baldwin. During its seven-year run, the show received massive praise and over 100 Emmy nominations for both itself and its cast members. And when the show finally came to an end in 2013, the series finale became known, per HitFix, as one of the greatest series finales in television history.

Almost 10 years since its last episode, 30 Rock is still beloved by many and is often seen as one of the best sitcoms of the 2000s because of its amazing cast of actors portraying over-the-top characters, jokes, and celebrity appearances. The show, in fact, had almost 200 celebrity appearances from almost any famous person you can think of, from actors and singers to politicians. Among the many guests were Apollo 11 astronaut Buzz Aldrin, Jon Bon Jovi, Robert De Niro, and Speaker of the House Nancy Pelosi. You name them, and they were probably on the show, and with a long celebrity guest list, there were some that stood out the most for either their memorable jokes or iconic references. As such, we made a list of 30 Rock's best celebrity guest stars and appearances.

8 Carrie Fisher

Carrie Fisher in 30 Rock
NBC

The late Carrie Fisher, famously known as Princess Leia in the Star Wars franchise, guest starred in season two's episode "Rosemary's Baby." She plays a comedy writer, and Liz Lemon's idol, Rosemary, that Liz gets the opportunity to meet and invites onto TGS to be a guest writer. However, she quickly finds out that her idol is now a washed-up writer who hasn't worked in years and who is out of touch with the way television is written in modern times. The highlight of the episode is her line that refrences her famous Star Wars line: "Help me, Liz Lemon, you're my only hope!"

Related: Tina Fey's 5 Best Performances, Ranked

7 Jennifer Aniston

Jennifer Aniston in 30 Rock
NBC

Jennifer Aniston guest starred in season three's cleverly named episode "The One with the Cast of Night Court" as Liz Lemon's sexy and chaotic friend, Claire, who has come to visit her. Donaghy (Baldwin) sleeps with her almost immediately after meeting her before Liz is able to warn him that she is unstable. Of course, he quickly finds that out for himself in the episode after she crashes his work party to sing him happy birthday, then threatens to kill herself when he tries to get her to leave. Despite this, he can't stay away from her even as Liz tries to help him and even as Claire becomes more erratic.

6 Steve Buscemi

Steve Buscemi in 30 Rock
NBC

You've definitely seen this guest appearance before. Steve Buscemi appeared several times on 30 Rock as private investigator Lenny Wosniak. He first appeared in season two's episode, "The Collection," but it's season six's episode, "The Tuxedo Begins," that became the most memorable thanks to the line that has now become an online meme: "How do you do, fellow kids?" Buscemi became a recurring guest star on the show, and while this specific episode is pretty short compared to the others, the iconic line has stuck around for decades, making him probably the most recognized guest star on 30 Rock.

5 Oprah Winfrey

Oprah Winfrey on 30 Rock
NBC

Oprah Winfrey appeared on 30 Rock in the season 3 episode "Believe in the Stars." When Liz Lemon is traveling to Chicago for jury duty, she takes sedatives for the flight and finds herself sitting next to Oprah Winfrey. While under the influence, Liz dumps all her problems on Oprah and ends up getting advice from her to help solve her current situation. In the end, though, it was all a hallucination from the drugs when they discover that Oprah wasn't really there and the person Liz was actually talking to was a wise 12-year-old girl when she swings by the studio to offer more help.

4 Jim Carrey

Jim Carrey on 30 Rock
NBC

30 Rock has a large roster of celebrity guest appearances in each episode, so it can be really difficult to include all of them in the storyline, but that's why you'll sometimes see them make their appearances through fictional shows and movies inside the show. Jim Carrey is one of those guest stars. The season six episode, "Leap Day," depicts the extra day of the year as a serious holiday, much like Christmas or Halloween, with parties, celebration, and a patron figure named Leap Day William. Carrey appears as a movie character, Dave Williams, in Leap Dave William's, where he slowly begins to turn into the real Leap Day William. Throughout the episode, clips from the fictional movie play alongside the main plot, where we see Dave William learn the true meaning of Leap Day.

Related: 9 Things You Didn't Know About the 30 Rock Cast

3 Steve Martin

Steve Martin in 30 Rock
NBC

Steve Martin guest starred as Gavin Volure in the season three episode of the same name. Gavin Volure is a rich and eccentric former CEO of Sunstream with agoraphobia that has kept him from leaving the house for three years, who developed an interest in Liz Lemon after he invited her and Jack Donaghy to his house for a dinner party. He turns out to be everything Liz is looking for; a man that she doesn't have to try too hard with and stay home to watch TV. He's perfect until it all comes to light that he is not an eccentric agoraphobe, but instead being kept on house arrest for tax fraud and arson, and was using Liz and Jack to try to escape.

2 Betty White

Betty White on 30 Rock
NBC

The late Betty White made her appearance on 30 Rock in season four's episode "Stone Mountain." When Tracy Jordan (Morgan) learns about the rule of threes that states celebrities always die in threes after hearing about the death of two celebrities, he becomes paranoid that he'll be the third one. He starts digging to check if any other celebrities have died yet until he decides to take matters into his own hands by calling Betty White, who at the time was 87 years old. She quickly figures him out, though, and shouts that she's going to live a long time and will be at his funeral with her funny yet ominous line, "I will bury you!"

1 Chris Parnell

Chris Parnell on 30 Rock
NBC

Chris Parnell became a recurring guest star on 30 Rock as Dr. Leo Spaceman (pronounced spa-CHE-min). He is described as being a physician with an excellent reputation as a doctor and a respectable reputation as a dentist according to Donaghy, but in reality his work is questionable at best. He claimed medicine was not a science, suggested crystal meth to Jenna Maroney (Krakowski) to help her lose weight, and after claiming there is no field of medicine that deals with the brain he suggests, again, to Jenna, to join a cult. The character was so outlandish and funny that he became a fan favorite, allowing Parnell to return for multiple appearances.