I think Half-Life 2 and the Metroid Prime games are FPSes, just not in the conventional sense. MP/MP2 (hey, the MP2 is a submachine gun!) is essentially a first-person action/adventure game where you happen to shoot stuff. Half-Life 2 is a more shooting-oriened FPS, but is simply more than that because it's so dang good. "FPS" implies that you'll be swarmed by half-intelligent enemies, but the Combine are really smart. Of course, it made the game really freaking hard, but it was worth it. I mean, okay, the eding could've been better, but you know what I mean.
But the way, Chup, I went blind after the 18th exclamation point.