I like it...but I don't do it very often.
I've got my eye on the EVGA 896-P3-1257-AR GeForce GTX260. Is that a good one?
I missed out on all of this geek talk. I recently got a new card and have been building PCs for people since about 2000, so I keep up very well on the stuff. The GTX200 series NVIDIA cards won't fit in my case so I was forced to go ATI even though I prefer NVIDIA. That said, I am very happy with my recently purchased (May-region) ATI HD4890, and it will out-perform the GTX260 for less moneys. The HD4890 competes directly with the GTX275, and last time I checked the ATI was a bit less expensive, but more importantly, about an inch shorter, allowing me barely enough clearance to plug in the power cords - which are poorly placed on the end of the ATI card but better placed on the side of the NVIDIA card. Now, since the 4890 is barely different than the
4870, but about $60-$75 cheaper, in your case I could easily recommend that, as it performs right with the GTX280, and you are looking at something like $145 for a good one (XFX) with a lifetime warranty.
My Corsair power supply is 620W and works fantastically, and I think the 520W would work as well, but I wouldn't go much lower than that. Corsair PSUs are made by Seasonic, who make some of the best, quietest ones around. Another nice thing about them is that they have lifetime replacement warranties, if you ever have a problem. Newegg is the best place to get the video card but the PSU can sometimes be found cheaper elsewhere.
You should be able to do the upgrade for quite a bit less than $300...
EDIT: There is a
sale on Newegg for Corsair PSUs at the moment, which will last for approximately 3.5 more hours, and there are some pretty good deals in there. As an example, if you got the 4870 and the CMPSU-550, you are looking at $235 before rebate and $205 after rebate...
EDIT 2: I just realized I am actually doing my best to talk you out of considering a PS3 because I hate Sony, but my advice still stands.