Buying gaming computer off craigslist, confused about which of these 4 to get.?

The one with the two 9800gt's in SLI is the best, followed by the one with GTX 260. I would go for that one because of the 500 dollar price. That's a fantastic deal for what's included. The other ones are crap and one doesn't even list the graphics card. What gaming computer ad doesn't list the GRAPHICS card?