1594 - The Hangover

It wasn't super important to me to re-watch this prior to seeing the sequel, but I hadn't revisited it since my first viewing, so I'd been meaning to check it out again anyway and see how it was on replay value. 
This is the kind of comedy that gets along a lot based on shocks in plot - a tiger in the bathroom, baby in the closet, naked dude in the trunk.  It's as if the writers were sitting around wondering just how messed up they could make these guys - and it works.  I know that I laughed my ass off the first time I saw this - an I know that going into the sequel that it's meant to be a bit of a carbon copy - so I'll be armed with that knowledge
I think plot surprises aside, this film holds up quite well, it's set piece upon set piece, but the chemistry amongst the three guys is just fantastic and the kind of thing that you can really build a franchise out of.  Great performances and solid writing (again, another example of storytellers fucking with their characters as much as possible.  I have to say that I'm a bit disappointed to know that Heather Graham will not be in the sequel - the romantic in me wanted her and Ed Helms to ride off into the sunset together.
If you still haven't seen this and you're in any way a comedy fan, it's an absolute must-see.
The Hangover (R-Rated Single-Disc Edition)  The Hangover (Unrated Edition) [Blu-ray]