If you want to bust out a song that people at the bar will sing along with, "Float On" and "Dashboard" are both excellent choices that at least half the crowd will recognize. Plus, there's no need to feel self conscious about how good you sound when you're singing a song that's three-quarters hollering. Then again, why not really test out your vocal range (and the bar's knowledge of excellent music) by belting out "The Good Times Are Killing Me"? It's a pleasant tune, but one that can get people all nice and rowdy if they're into drinking ironically. On second thought, just sing "Doin' the Cockroach" and weird everyone out for few minutes. (Dance moves optional.)