This is Toms' Hardware graphics chart. Note they say not to upgrade unless it is at least three steps higher. For your 560TI, that would be a 670. The 560 or 660ti are only two steps up, not enough to be worthwhile. Of course, you could go four steps up to a 680. Right now the sweet spot for Nvidia is the 670, 95% of the 680 at about 70% of the price. I'd go with the:http://www.newegg.com/Product/Product.aspx?Item=N82E16814125423
GIGABYTE GV-N670OC-2GD GeForce GTX 670 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support Video Card
It is a paltry $330 dollars now.