I spent all night reading reviews and comparing cards. If your looking at spending in the $250 range I would recommend either a gtx570 or gtx580. Both cards outperform the 6950 and 6970. They also seem to be generally recommended over the 6950 and 6970. Since reading extensively on all 4 cards I can see that the 570 and 580 run cooler and quieter also. Here is a link to a 570 with a lifetime warranty.
Newegg.com - PNY VCGGTX570XPB GeForce GTX 570 (Fermi) 1280MB 320-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
You can find these very close to $250 However I recommend this one because of the warranty.
Newegg.com - PNY VCGGTX570XPB GeForce GTX 570 (Fermi) 1280MB 320-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
You can find these very close to $250 However I recommend this one because of the warranty.