EVGA GeForce GTS250 vs. EVGA GeForce GTX260

I have a Dell Dimension 9200 desktop computer and with all these great games around that I want to play, I am in dire need of a new video card. The one that I have now just isn't doing the things that I wish it would do. I am debating on whether to get the EVGA GeForce GTS250 or the EVGA GeForce GTX260. I am not worried about the price, I am only worried about whether they are compatible with my computer and how good they perform. Is the extra cash for the GTX260 really worth it? Is my PC compatible with running both of these? Or will they even fit in my PC? I'm sorry that I'm not good with hardware, but could someone please help me decide which to get and tell me if my PC is actually able to use them? Thanks!

Ok first u have to make sure u have 500watts at least for gts 250, and 550w at least for gtx 260.

2 you have to make sure u have a pci express x16 slot, Open up ur case there should be a very big slot to connect the motherboard with the video card together.

3 Get gts 250 as its less power demanding and the difference is only a 10-15 percent gap.

the gts 250 is also quite a bit smaller.