Probably Lobo because he's just ridiculously powerful, and his healing factor is really something to contend with....but I like Hercules A WHOLE HELL OF A LOT more than Lobo.....
I mean, Lobo has smacked gods around before like nothing, so what's stopping him from slapping around a half-god like Hercules? Sadly, Lobo wins, but Herc is soooooooooooooooooo much cooler!