HP or Gateway?

I've had my Gateway desktop for about 4 years now. Windows recently crashed on it and the repair installation didnt work and reformatted my whole hard drive. So now I'm thinking it might be time for an upgrade anyway since I can get twice the machine now for the same price I paid for mine when I first bought it and instead of reinstalling all my software on the old machine just install on a new system.

I was looking at either an HP or another Gateway since I hadnt had a single problem with the Gateway till now and rather liked the system but heard that HP might be a higher quality system. A system with the same specs is more expensive with the HP tag than the Gateway tag and i want to know if the system and performance really justify the added cost.

I want to get a quad core processor, at least 3G of memory (prefferably 4G), and 500GB hard drive or better. I'd also like one with a good Nvidia graphics card since I frequently do a lot of graphic design type work.