Dxtory is very good, though I seem to get frame rate drops with it when recording - but when uploaded to YouTube, my file plays fine at 60fps. I may have it set up not quite right, though.
Mirillis Action is another I like.
D3D Gear is also good.
ShadowPlay is a very good way to keep great performance while you record, resulting in reasonable quality - though not as good as some others in that department, imo. However, as I'm sure you already know, you'll need an Nvidia card for that to function.
AMD's Raptr is also reasonable, though I didn't find it as reliable as most of the others already mentioned.