The Hangover was one of the funniest movies I've ever seen, period, and I saw it sober. Great idea, good character mix, different kind of humor, not all formula crap. Took me back to a few nights back when drinking and driving was an accepted practice many years ago, and some of the situations we found ourselves in (to a lesser degree, of course).
I also thought Pineapple Express was hilarious. That scene in the guys house where they were fighting is one of the top 5 funniest scenes ever, IMO. I don't expect Hot Tub to be on par with this one, seems like more of a Dumb and Dumber scenario plot thing to me, not that I didn't laugh at that one, too...