Play your standard 'social' songs, like "You Shook Me All Night Long" and "Brown Eyed Girl". If your band's got the talent to play some Doors' songs, they'd go over pretty well too, I think.

Oh, and anything by CCR. Bar-goers love CCR. Assuming, of course, that we're talking about a dingy little pub, and not some high-society, name-on-the-guest-list bar.