Brian never did anything funny. Yeah, maybe he was Stewie's straight-man, but whatever. He hit on Lois whose husband supported him, seriously dated the airhead Jillian, was an annoyingly self-righteous liberal. The only thing I sorta liked about him was he was a martini swizzling alcoholic. Quagmire really said it right.
http://www.youtube.com/watch?v=n44L0EqNz5Y