He doesn't have much range, per se, i mean every performance is a Tom Cruise performance (including Magnolia, just a bit more hyped up than usual), but fuck man...nobody can do the shit he can do. He's Tom Cruise. End of story. He is Tom Motherfucking Cruise. Nobody else can do the wide eyed, jaw agape, staring off into space, thinking intensely, then bursting into a screaming fit proceeding to curl up on the floor in hysterics better than him. Plus I don't think I'd want to see anybody crawling across the top of a speeding train, wrestling with John Voight, more than Tom Cruise. There are several other actors who are all their own in every film in that sense (harrison ford, woody allen, etc), but y'know, who the fuck else would we want to see do it?
Tom Cruise is a terrific actor.