I use FRAPS, but it does make huge uncompressed files. It also causes some lag during recording. So that means, you'd have to dedicate a whole hard drive to your FRAPS recordings. The quality is the best, and it's simple to use (for me at least).
There's also MSi Afterburner, which is great! It's like FRAPS, but you can also overclock your video card with it.
DxTory is great and it compresses videos as you record. The only downside is that the interface isn't as user-friendly.
Action Mirilis is also great, but I haven't used it as much.
You could also go overboard and get a recording capture card like an AverMedia Live Gamer Portable. You could record console, and PC. It's also great for livestreaming. The card barely uses any CPU resources, and the quality is great! It's expensive though.