For $1000 you aren't going to get the most top of the line gaming laptop, but you can still get one that plays current generation games pretty damn decently. I recently got the following laptop for just under $700:
http://www.amazon.com/Acer-AS7741G-6426-17-3-Inch-Laptop-Black/dp/B004G5ZXH0/ref=sr_1_1?ie=UTF8&qid=1314682708&sr=8-1
It has an i5 2.66 ghz processor, 4 gigs of ram, a 640 GB HDD, and an AMD Radeon HD 6550M graphics card.
So far this computer has been able to run anything I throw at it without a single hick up and it can play both Crysis and Metro 2033 on high settings with a playable framerate (as well as playing Deus Ex, TF2, and Fallout New Vegas all at 60 FPS easily.
It does however have some downsides. If you're going to use this computer to game you REALLY need to invest in a cooling pad. Not any cooling pad, because all the vents on this laptop are on the left side, so you'll need a cooling pad that you can reconfigure so that all the fans are on the left.
The HDD isn't so great either. While it has some pretty decent storage space at 640 gigs, it isn't that fast, running at 5400 RPM.
All in all it's a great budget gaming laptop, but you shouldn't expect it to last you more than a couple of years. The parts aren't top of the line, and aren't as reliable as you would probably like, but it's all about compromise, cheap power versus reliability (but then again, in 2 years computers will probably have increased in power enough that you'll want a new one anyway).