Lol I tend to buy things "on a lag" too. Its ok I just can't afford all these expensive games!
If you're ok with a used one, then I would go for something with nvidia 500m or 600m series, at least 512mb dedicated but a whole Gig would do you well, at least 4 cores on the CPU, and 4-8GB of ram. I would HIGHLY recommend getting an SSD because they make a world of difference as far as general responsiveness goes. You should be able to find something like that without a SSD for $400-$600. Its not a big deal to add a SSD to one after you buy it. A nice new 250GB one from Samsung will run you about $90 depending on the exact model.
I forgot to mention above that samsung and sony are good brands too, they just don't really make "gaming" class laptops. Mostly just really nice normal-ish ones. They do make models with gaming cards in them, they just don't market them as gaming laptops