I hate to seem like an ass, but couldn't you just look on site like Gamespot and check there? I mean, there are only a handful of titles out now so it wouldn't take so long. I'd think Resistance would have split-screen, and maybe the sports games.
You know why I can't find out and why I haven't gotten an answer yet? Cause it's hard to find out! Seriously! They don't spell it out in plain English for you. All they say is "multiplayer", and it doesn't tell you how many players it supports or if they're talking about online or not. I HAVE tried already! Countless reviews also simply say "multiplayer" but doesn't actually say how many players.
Go to GameSpot, then click on the review for the game you are interested in, and then click on the "Tech Info" link by the number grade and it will give you a whole bunch of info about the game including multiplayer numbers. There's always Google if you can't find it on GameSpot.