I'm not talking a movie as a whole. Or a one liner but a extended scene or complete sequence.
7 psychopaths when Sam Rockwell gives his version of the screen play is my official nominee. I mean that was just nonstop laughs. I was dying. I can't find a video yet since the movie is still new.
A couple other ideas.
Home Alone 2. When Harry gets the bricks thrown at his face. It slayed me when I was younger. He gets beaned multiple times and then gives the unforgettable "Harry,. . .harrrrry." speal.
And the "other guys." When Will Ferrel goes off on Mark Wahlberg about trying to be Lion fighting a tuna fish.
Step Brothers being the GOAT comedy has several nominees including the fight, the bonding, the job interviews.