Aliens definately wins, with Alien following up with a close second. And don't waste your time with resurraction, unless you simply HAVE to fond out what happens, becasue they toatlly screw up everything that was good about the first two (and maybe even three). :/
AvP was'nt wonderful, but it still had some memorable fight scenes and some big, bad Predator moves. If you're a die-hard fan of either the movies and/or the games, I'd go see it.
Just curious though, I know AvP was less gory than its predecessors, but don't you still think they were pushing it to give a PG-13 rating? It seemed fairly borderline to me.