Best funny movie

This is a hard question. To be honest, I do find myself a fan of the "so stupid it's funny" comedy. I really like Tommy Boy and Dumb and Dumber. Although, Ace Ventura is really great too. Jim Carey is pretty ridiculous in that movie. In fact, there is this one scene in Ace Ventura when Carey is doing a rewind and then slams his head on a table. If you look closely, you can see Courtney Cox's shoulders moving up and down rapidly as she is trying everything she can to hold back her laugh. That scene gets me every time.