I agree. The 560 is a great buy!
If you want to go the AMD route, grab a
Sapphire 6850.
I switched out my 460 (which I loved) for this (because my board supports Crossfire only) and I also love this card! It easily overclocked through Overdrive to 925MHz and it only hit 63 degrees under high stress. Note that I have a well ventilated case.
After rebate you're looking at $134. Both this and the 560 that solomonshv mentioned are great cards.
A decent site that I use for comparison is
videocardbenchmark.net, however this should be taken with a grain of salt since it does not detect over and under-clocks as well as other system specs that might be bottle-necking performance.
Have a nice day!