50. The Hangover (2009)

Director: Todd Phillips
Writer(s): Jon Lucas and Scott Moore
Actors: Bradley Cooper, Ed Helms, Zach Galifianakis, Justin Bartha, Heather Graham, Ken Jeung
Quotable:"Remember, what happens in Vegas stays in Vegas. Except for herpes. That shit'll come back with you."

Complex Says:

The Hangover blindsided Hollywood execs and audiences alike in the summer of 2009, laughing its way into history books as the highest grossing R-rated comedy of all time. How? It's simple, really: Prior to its release, the comedy genre was stagnant, devoid of event movies since 2007's Knocked Up. That all changed, however, courtesy of a one-man wolfpack, a bizarre yet effective Mike Tyson cameo, and a baby jacking its little weenus. Phillips' comedic mystery—about three groomsmen trying to locate the groom after a night of hard partying in Las Vegas—used its detective story veneer and subversive unpredictability to show that a high concept is more important than big-name stars. It also doesn't hurt to have Zach Galifianakis on board to drop quotable after quotable, or a manic Ken Jeung as your villain.

Fun Fact:

Heather Graham's stripper role was originally offered to Lindsay Lohan, who turned it down, thinking the movie would be a flop. Just one of Lohan's many intelligent career decisions.