With having a twin, most of my games are splitscreen. Halo: Reach and Black Ops were great as the second player didn't feel tacked on. It's the same with Borderlands. Hell, Gears of War GAVE you an achievment for playing as player 2. The best is, by far, Nightfire though. Gosh, i spent most of my childhood on that game. Also the Star Wars Battlefront games were great fun on splitscreen. It's nice when a game has a splitscreen campaign, Splinter Cell Conviction. Or when a game is JUST offline, like Shank.