I agree Worf is a kind of a underrated source of humor. Lots of funny one-liners and jokes about how serious he takes things. Of course this though can also be more of another vote for DS9 since he was a regular on that show. It's almost equal but DS9 also took him more serious as a kick-ass warrior where he doesn't get beat up in a fight every week which might have diluted the humor somewhat. He was a more welll-rounded character on DS9 but on TNG they almost where always going for the joke with him except in the Klingon ep's. so I would still say he was more funny on TNG but they still got some good Worf humor as well on DS9.
Jason
Jason