Tough call, but I reluctantly go with Dean Martin. He was not half as good a singer as Sinatra, he could not dance like Davis, Jr., and he was as unfunny as Joey Bishop (does anyone have Joey as their favorite??? how did he even get into the rat pack?) and he was not the drunk that Peter Lawford was. Instead he was sort of the consumate rat pack guy. Always had a cigarette going, alsways half bombed, or appeared to be, always hamming it up a bit when crooning...a real lounge lizard.