What kind of gaming will you be into? Apart from the price range, is there any other condition you want fulfilled? Screen size? Wireless connectivity? Specific game o benchmark score?
The processor on the Alienware in the above post is old technology, in my opinion.
I'd also take a look at http://www.killernotebooks.com/ (haven't bought from Mark yet, but looking into it; great performance notebooks and best customer support I've heard of, before and after purchase).
I second the Killer Notebooks, I have bought an Executioner from Mark. Both his notebooks and customer support are great. However, the price is outside of your budget, but you can always talk to him about the Wakizachi, which is decent for medium (like WoW) games.
I agree with Theworminator. I didn't buy from Mark but he answered every question that I had and the responses came quickly. He was willing to cut me a deal on the Executioner, but I couldn't take him up on it (long story). The Wakizachi would be a good fit.
The Wakizachi escaped my mind when I posted the first time. When I think of K|N, the Executioner, Odachi and Assassin always pop in my head and they are WAY out of his price range. Then again, send Mark an email and see what he can do for you.