I haven't seen it yet but I hear Superbad is very funny. It's on my list to see this month, for sure. I liked Stardust a lot as well, but it's more of a feel-good movie than a comedy.
SUPERBAD!!!!!!!!!! My friends and I thought it was hilarious. You have to get in your "adolescent boy" headspace to enjoy it though... I really felt like it was one of the most true to life, best written teen movies I'd ever seen. The entire time I kept thinking to myself "wow, that's totally what my guy friends are like...except these guys are funnier." I highly recommend seeing it.
I don't know if "Knocked Up" is still in theaters or if you have seen it or not, but it is hilarious and perfect for our age group.
I also want to see "Superbad" this weekend because I love absolutely corny movies like that (I'm thinking it will be in the same vein as something like "Harold and Kumar go to Whitecastle").
I can tell you one to avoid at all costs...I Now Pronounce You Chuck and Larry. I decided to give it a shot because Alexander Payne (Election, Sideways, etc.) had screenwriting credits. It was so bad I fell asleep.