I know El Shaddai is a good deal, but I tried the demo and I just didn't get it I guess. I really liked the art style but I just don't know.
I'm leaning towards MK vs. DC even though I don't like fighting games that much. Mortal Kombat is basically THE only fighting game I've ever liked, but I know this one is toned down because they weren't allowed to "kill" the DC characters
I have most of those games. I would say Tomb Raider, Dark Messiah, Call of Juarez, in that order. Personal preference of theme/setting play a big part in choosing though, they're all well worth it. El Shaddai is not very good, imo, despite the interesting visuals it plays pretty horribly. Grid is not even in my top ten racers this gen. Dirt 2 s better of the two IMO, but I don't love that either. I have no real opinion of K&L or MK v DC.
The writing was on the wall with Bioware the minute you could completely void all of your decisions with one choice in KOTOR.