halo 3 all the way for me. For one the single player doesnt suck, cept maybe halo 2, but still it pushed you to see the ending so badly, that it set the series up for halo 3. and according to bungie when they let the press see it, one of the press members said that the ending was perfect. then aside from single player, theres multiplayer with xbox live and the map editor (forge), not to mention saved films which you can take screenshots from and upload them to bungie.net and do whatever you want with them. Halo 3 will outlast any game.