I'd shoot for the Dell, as they are more reliable over HP laptops, at least in my opinion. Plus, the GPU in the HP is more for 3D, design, etc..., not for gaming. You'll see the best results with the Dell for sure.
I actually found another laptop with better specs than the Dell and the HP.
It's the Asus n61jq
It has 4 gb ram (dd3)
Radeon 5730 (which is supposedly a spruced up 5650)
What's your opinion on Asus laptops? This one seems really great for the money. The screen has a somewhat low resolution of 1366 x 768, but I don't mind because my current (rip) vaio has a res of 1280 x 800. It also has usb 3.0 and an hdmi port, so I could always hook up my full hd lcd.