NVIDIA GeForce FX 5600 VS ATI Radeon 9250

So i suppose its a fairly straight forward question , which is better? Im using a celron 2.50GHz CPU if that matters.

If they are free, then take the 5600, as it should be better, but if you're using an old Northwood desktop celeron 2.5 GHz with 128 kb L2 cache, it really won't matter which video card you get, b/c your bottleneck is that cpu. Old Northwood desktop Celerons are absolutely terrible for gaming. They lose to a 1.6 GHz Duron. Your celeron is pretty much equivalent to a 1.2 GHz Tualitin Pentium III when it comes to gaming, it's that bad.

If you're looking to buy either one of these graphics cards for the going rate off Newegg, then I suggest you take that money and buy a used GeForce4 Ti4600 off ebay, as it is in this same price range (~$25-$35), and mightily kicks the crap out of either of the graphics cards you are currently choosing between.

Im gonna have to go with the 9250 if you had to buy 1 of them, being that the price is lower, but ATi customer service is terrible.

Lets see : Celeron 2.5Ghz CPU
Geforce FX 5600 GPU
P4P800 SE mobo
512 Ram
2x 5.99G HD 1x 80G HD
Thats about it not counting Cd drive ethernet card and sound card.

Im looking at the intel pentium d 805 dual core CPU , will that even work with my mobo?

I've only had good experiences with Ati customer service. They have always dealt with me in a timely manner.