H3: Best Co-op (4 player ftw)
H3: Best Films
H3: Best Design your own map layout
H3: Best fun minigames (rocket racers ftw)
H3: Best online integration of stats with Bungie.net
I'd agree that H1 has the best "Campaign story".
Gamers have 3 choices this generation: The Exercise Machine, the Movie Machine, or the Game Machine. What kind of gamer are you?