1. It didn't have the predictable cast of dude comic actors (e.g., no Bill Hader, even though I think he's funny.)
2. I have never been to Vegas.
3. Zach Galifianakis.
4. it's summer, and my critical acumen seems to drop as the temperature rises, hence i am able to almost ignore the fact that there are, like, no women in this movie.
5. that ridiculous wedding band singing about nymphos.
6. the trunk scene.
7. the breakup scene.
8. Ed Helms's non-cosmetic toothlessness (thanks to E! for this tidbit)
10. it combines hi-jinx with mystery, with a little narrative help from roofies.