SLI-Ready is the new thing. If you want cheap and good upgrades check these out:
http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=2824015&Sku=A455-2320&SRCCODE=YAHOODF&cm_mmc_o=QztBBCjCVRqCjCVRqCjCVRq
(Also available with Intel)
http://www.compusa.com/applications/searchtools/item-details.asp?EdpNo=3433267&Sku=E145-8816&SRCCODE=COMPYAHSDF&cm_mmc_o=QztBBCjCVRqCjCVRqCjCVRq
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3079597&CatId=2261
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4148715
I've always been a huge AMD fan and don't plan on changing soon, so don't hate cause I know Intel's better, now :P.
Cheaper in stores than the internet, of course. I'm going with these (except the processor) and eventually putting another identical vid card and another 2 gigs of RAM. Like I said, good upgrades and they're cheap.