Splinter Cell is ALWAYS a riot in co-op.
Usually, in single-player, you have no choice but to play it stealthy, otherwise suddenly you're taking it up the butt from legions of AK-wielding bots.
In co-op,suddenly, it's a game of harassment, amusement, torture and just plain trolling. Those poor AI didn't stand a chance. Want to capture him? Get you mate to whistle in one direction, and when he tries to find him you sneak up behind him and grab him by the nuts. Two players and a bot in a dark room is a recipe for trolling. Poor bugger just about goes out of his mind when both of you fire the sticky cameras and whistle and click and gas the room. And you can somewhat pull off an assault strategy, with two of the machine guns and twice the number of targets for the AI, you can deal out far more pain and they won't last long enough to do anything.
Other good games are Resistance, because you play through the good single-player. Bonus points for using the sniper rifle to slow down time (yes, the sniper rifle makes time slow to a crawl) just as your mate is about to make a kill, causing him to fail.
Motorstorm: Pacific rift is also good, because it's got the usual delicious motorstorm gameplay but with split-screen you've got a partner in crime or a prime target (or both). Just avoid the first motorstorm, which doesn't have split-screen).
Hope that helps.
