The following Lenovo IdeaPad Z570 with a Core i5 and nVidia GeForce 520M is probably your best best for $650.
http/www.newegg.com/Product/Product.aspx?Item=N82E16834246156
If you want to spend less then the Acer Aspire AS5750-6438 comes in at $580. It has a Core i5 CPU and the integrated Intel HD 3000 graphics core.
http/www.newegg.com/Product/Product.aspx?Item=N82E16834215115
I have a Lenovo IdeaPad Y470 with the same Core i5 CPU as the above laptops, but it comes with a nVidia GeForce GT 550M i(t is out of your price range). I am in the middle of writing a review for and I have tested Crysis using the Intel HD 3000 graphics core.
As you may or may not know Crysis is a pretty demanding game. With all graphics options set to low and no anti-aliasing, the Intel HD 3000 graphics core was capable of playing the game. I was playing the game for around 90 minutes. The lowest I've seen the frame rates go was 16FPS, but that does not happen very often. The highest I've noticed is about 29FPS, but again that does not happen very often. On average during that 90 minutes the frame rate ranged between 19FPS and 25FPS.
Setting anti aliasing to x2 kills the frame rates to between 8FPS and 11FPS during the few minutes I was testing it. Needless to say, that is definitely not playable at all.
The testing was done during the 3rd Chapter in Crysis; Relic.