Help on GTX 260

Buy an evga or an xfx. Better warranty. Unless you have an sli board you might consider a hd4890 or wait a bit for a gtx 275.

Get the gtx 275, it costs as much as the 260s used to.

I have an AMD 790GX board. But the HD 4870 1GB are a bit out of reach. I want to keep budget under 190-200. EVGA and XFX are all $210ish and then 190 after a rebate I can't get for sure. GTX 275 is out of range as well as the HD4890. Plus, I don't think my PSU can handle the increased wattage needs of the two new cards.

Get the 4870 512mb - they sell for about $140-$150. The 1GB version on newegg sells for about $180-$200

You have to watch EVGA. Some of their products no longer have life time warranty.

I'm going to be running at 1920x1080 so I think at least 1GB is necessary if I go ATI.

That is correct, but all there mid to high level graphics card fall under lifetime warranty. Basically anything 150 and over with few exceptions. XFX by far has the best warranty of them all.
http://www.evga.com/support/warranty/

Well honestly till I just read the new warranty, I thought EVGA had the best overall. But still, if I had to chose between an EVGA card w/Lifetime Warranty and an XFX, I'd still pick EVGA. Warranty not considered? I'd pick the cheapest or best value, Which has been MSI quite a bit in the range of products I've considered.

Oh, and all of EVGA's GTS 250's(listed on Newegg anyway) have a 1+1 warranty now.