I may be a little late to the party here, but Mirror's Edge is so good!
It took me a while to get it working, since having PhysX (graphics engine) enabled caused some trouble, but the game itself is really good. Sure, the storyline's engaging, and the art style's really pretty, but that's not what makes it so awesome.
Mirror's Edge is a game in which you jump across rooftops and escape from cops. Basically parkour, except in a video game. It feels really fluid, and it's great to just jump great distances, land, roll, and keep on running!
There's combat as well! Usually you can just run away from the cops, but sometimes you get a little confrontation going. You can either tactfully disarm them from behind, or face them head-first. The combat's a bit iffy, and I usually end up just clicking rapidly in the hopes of knocking them out in time. Still, the satisfaction of knocking out a cop is surprisingly great!
It looks pretty realistic, too. The cutscenes have their own cool style to them, but the gameplay is, overall, quite realistic!
And all that for only ten bucks on Steam. Go get it now!