im putting in another for shadow complex that game is great

Thanks guys for the suggestions. I decided on SuperMeatBoy and withholding some of my other points while I try out all the other demos.

vaguely unrelated: do i have to have the dead rising 2 disc to play case west, or is it separate like case zero?

I'm assuming you already have Geo Wars 2...if not FOR SHAME!

My favorite XBLA exclusives that I think you should try the demos for: 

• Shadow Complex
• 'Splosion Man

• Super Meat Boy
• Dead Rising 2: Case Zero
• Carcassonne (currently on sale for 400 pts)
  

• Dead Rising 2: Case Zero
• Soul Calibur
• Marvel VS Capcom 2
• King of Fighters 98
• Samurai Shodown 2´
• Comic Jumper

Super Meat Boy, Pac Man CE DX, Shadow Complex, or if you have Bad Company 2, Vietnam is amazing.

forget raskulls its too short

Super Meat Boy is fantastic. Try Limbo before you buy it. I thought it sucked, it seems to be kind of a love-it-or-hate-it game. Shadow Complex started out really good for me, but then I got stuck in this part with no possible way out, so I'm kind of annoyed by that. Stupid respawning enemies! I need to start it over completely, and luckily I wasn't that far, but I haven't done it yet. 
 
Braid is excellent if you like adventure puzzle games. It's very cool, just don't use a guide because you'll really take the fun out of it.

Get naked and rub them all over yourself. Slowly.

I recommend Limbo, Shadow Complex, Super Meat Boy and Braid

Shadow Complex and Super Meat Boy are probably the top two. Is Limbo an exclusive? I can't remember.

Shadow Complex is pretty much one of the best exclusives I can think of. 
  
Maybe Limbo? Maybe one of those Dead Rising downloadables?

If you like shooters you should get Gunstar Heroes. It's only 400 points.
 
Super Meat Boy is great, totally worth the 1200 points. And if you've never played it, Doom II is another great choice. I have lost many hours to that game.

Thanks to GameStop's PowerUp Rewards Program, I now have two 1600 Point Microsoft cards. I'm trying to think of what to use them on though. I know the 360 has a ton of great XBLA exclusive titles (any others I have on PSN already, trust me). I was thinking Super Meat Boy, but for 1200 points, I'm not sure. The demo for Shadow Complex was pretty good. I might look into getting that. I loved the demo for Raskulls, so that's probably a for sure buy. What else should I get with it though? I'm looking for great XBLA exclusives here. I'll go digging tonight...