Any of the Halo series. I am so sick about hearing about them.
Yes, I've played them. Each one is exactly the same as before, but with one new flavor added to the dull pot of porridge.
Halo: neat
Halo 2: wow, dual wielding guns. *yawns*
Halo 3: Wait, so I can pick up the gun pod? That's it?
Halo Reach: Whoopie, we all gonna die. Oh, look, jetpacks for like 10 minutes.
I'm not even gonna comment on ODST or Halo Wars. Played 'em, hated 'em. And could care less about the multiplayer. I played it for each, and it's pretty much the same FPS multiplayer game that's out there for every other game.
And it's sad, because I love FPS games. Could have been epic. First game came close, but all the others were simply carbon copies. And over time, it actually detracts from the game.