Crysis will stretch your machine's abilities to the breaking point and then promptly drop a 10,000lb weight on the overstretched surface. Its a beautiful game and if you are really into graphics it is nice. The gameplay itself was a bit "meh".
If you are into games that are more focused on gameplay with fast paced speed, you could go for something like TF2 or Unreal Tournament 3.
If you want all that fun gameplay and good graphics for free you should check out 2 games:
Warsow: www.warsow.net It has a "cyberpunk" look to it and uses cell shading. Looks pretty neat and is fun to play.
This one plays kinda like a cross between quake 3 arena and Unreal Tournament. Lots of fun and you can really crank the graphics (to have things like HDR, dynamic lighting, light bloom, etc).
Both of those games have pretty active communities and are freely downloadable.
And then of course you have oldies but goodies like tribes/tribes2 and quake 3.