The Lord of the Rings - the reason we love this clip is the full on shenanigans of Ian McKellen are absolutely hysterical. 


Liar Liar - I don't care what anyone says about him, you CANNOT beat Jim Carrey. These bloopers show the stand-up side of Jim that the world fell in love with!


Step Brothers - an epically quotable movie that understandably comes with a huge number of adlibs - we love the John C. Reilly and Will Ferrel pairing!


Seinfeld


Arrested Development


BONUS: Kevin Spacey's absolutely incredible and dead-on impersonations