Crysis. Do I have to say any more? The gameplay has gotten some really great reviews. The gameplay looks a lot more fast paced and more cinematic than any other game on the market. Oh, and it's the best looking game ever made!
Here's some screens (fully rendered in game; to run it this good you'll need a really, really good computer):
The physics look really amazing and so do the shaders. All the textures are super high-res, too. They can be blown up to 3xxx*2xxx and still look amazing. The gameplay looks like a nice change to the typical shooters these days, too. I'll probably play it next year when I get a new computer.