The one with the barbershop quartet singing about vasectomies. I like the black guy.
For the record, Family Guy sucks in general though: most of the humor is overly crass and irrelevant. I’ve seen jokes they use in other places before they air it, too. Most of it just comes off as obnoxious, though. So for me, my favorite “episodes” are really more of favorite moments that shine above what is otherwise a pointless annoyance where every young person I know idolizes it similar to the way 9 year olds go ape shit over Hannah Montana.
ducks and waits for people to tell him how awesome family guy is, and how he is going to burn in hell for being a naysayer