40 year old virgin is one of the greatest comedies of all time, especially for dudes in my opinion.
It's got everything...bro mances, dick jokes, physical gags, great funny story, sarcasm, archetypes (both guy and girl), one liners, memorable situations, and its filled with pretty much unknown comedians at the time that now are considered big stars (Carell, Rogan, Elizabeth Banks, Kevin Hart, Paul Rudd, Apatow's wife, Jayne Lynch, a teenage Kat Dennings, Jonah Hill when he was completely unknown).
You can't go two minutes in that film without a laugh out loud moment, it's one of the most quoted comedies (from now on your d#$k is my d#%k, Kelly Clarkson, a bag of sand, it's not about the p&$$y juice cocktail, that f$&ker came out of nowhere, do you know who I know you're gay, Hi my name is Gina).
It's a great comedy. That being said his other comedies are good but not anywhere close to the 40 year virgin IMHO.