Halo 3 for a bunch of reasons. Love the dual wielding and all the cool weapons like Brute Spiker, Flame Thrower, Mauler, Spike Grenade, and Flame grenade. Also the different vehicles made it fun. And because of the better playlists. Multi Team was by far my favorite as well as Team Dubs. Zombies was better in Halo 3 as well. Flood just isn't as fun as zombies was. There's not enough people and there's no custom maps specifically for it either. One main reason though I prefer Halo 3 MM to Halo 4's is because I feel the precision weapons you spawn with dominate MM and leave little room for anything else.