[bigiain]

If you can pull it off, something like "Really? I thought you were smarter than that…" works pretty well. You kinda need to be able to dominate the conversation with the comment though (which is often pretty easy if it's just one jerk speaking out of place, but can be much harder if they've got an audience-of-idiots laughing along with them).

One thing to keep on mind - the "offender" has given up any expectation or right of politeness or manners extended towards them - there's no need to craft a response that doesn't hurt their feelings, since they've already gone down that path. (I suspect if I were just the right amount of uninhibitedly drunk, I'd quite enjoy responding to "She only got the tickets 'cause of her tits" with "Yeah, that's what everyone with a tiny dick says…")