Halo 2 and 3 ONLY because of the community during that time. I enjoyed 4 and love 5 but, the toxic community makes enjoying the game hard. Hardly anyone communicates and the ones that do are arrogant pricks or 10 yr olds who don't know wtf they're doing. The games have evolved and gotten better IMO but, Halo 2 on Xbox Connect (look it up) and Halo 3 were more enjoyable to play because most of the player base used a MIC and communicated or at least paid attention during a game and knew callouts.