I've been using my GTS 250 for years now and it still serves me well. I manage to run games on medium downsampled to 1080p, however I'd like a little more than that. I want to be able to run games on high (or maybe ultra) on at least 1080p. I've been out of touch with new hardware for quite some time and I really have no idea what would be a decent card.
My budget is around $200, however less would be nice. I found a GTX 570 1280MB DDR5 for $170, but I'm not sure if this would be enough or more than I need.
In my opinion the 660 is worth the extra, you get better performance, more vram, some features that only the 600 series got, and lower power consumption.
The rebates, i don't know if it is reliable or not.