Or if you want something less expensive this is very good, just upgrade the ram to 2gb when you cna (another 1gb stick costs ~$110)
Make sure whatever you buy that you get a good dual core processor, 2gb of ram, and above all a good dedicated gpu. The grafix card is going to the be biggest performance affecting feature in your notebook so you've got to get a good one.
Sony and ABS can make really nice gaming laptops for substantiall less money than places like Alienware. I don't really like Dell unless you're going for the really high end stuff.