depends what sort of band you are, IMO it's no good trying to please everybody, people get bored with the stuff they don't like, focusing (more or less) on one genre and you'll attract that sort of crowd, for instance Ska is very popular.
I'm in a punk band, but we do stray into heavy rock (whole lotta Rosie) and the novelty songs are popular, Jilted John and Nellie the Elephant, basically people love to sing a long and dance, I'm talking about pub gigs btw