I adore Iron Man, and I'm going to say X-Men in this case. IM sort of needs variety around it. It is a wonderfully brutal game that gives huge satisfaction when you hit your shots. Bit that brutality needs something to offset it. Without that, it might get old quick. X-Men has much deeper rules. It is more involved. Personally, I don't like the game (I've never enjoyed playing it), but in a 2 pin collection, I'd get to know it a lot better.