I like Wilson's US Open (or the Australian Open) balls the most.
Some people say Slazenger's balls are the best, but I think there's far too much fibres sticking out of the balls. Just don't look good.
Pro Penn, Gamma ProTour, X-One (the most lively, but doesn't last)
HiVis, TF Club, US Open (good Price-to-Performance)
Slazenger VS, HEAD ATP (constant bounce, and fast, quite durable)
Dunlop Fort (durable, slow kicking but not come through)
AO (hate most, last forever, but playability is the worst)