That's right, E!'s tallying up the top nine sitcom guest stars from over the years and the picks will without a doubt surprise you.
Who could forget the moment Cher and Sean Hayes tried to out-attitude one another during an episode of Will & Grace? And how ridiculously amazing was it that none other than Mrs. Beckham herself was dubbed "perfect spice" on Ugly Betty?
Of course, the moment when Tina Fey was on an airplane sitting next to Oprah Winfrey on 30 Rock was a pretty special moment, and we gotta hand it to both ladies for being able to keep a straight face for the hilarious scene.
But if there's one guest appearance that tops the rest, we have to give it to Pitt, who broke hearts around the world when he showed up on then-wife Jennifer Aniston's hit, Friends.
Enough from us, though. Take a look at the clip above for even more amazing sitcom guest star moments!