There's fraps, which I would personally recommend.
Down side - Large file sizes, only a problem if you don't have a lot of hard drive space, but you should be editing your video down and encoding it anyways.
Upside - Probably the best quality of any game capture software.
However, there are a couple other options. I haven't been able to configure most of them correctly though, besides dxtroy.
Dxtory (Similar to fraps), playclaw (Have never tried it), Bandicam (Low file sizes, but I could not get it to capture my sound), wegame (Requires a monthly membership for HD I think), and xfire (which seems to drop my frame rate a lot.)
I'd honestly go with fraps, but if that isn't your bucket of chicken, I would try dxtory or Bandicam.
Fraps is good as long as you can edit out the bumps inbetween files, and have a good software to convert it to mp4/mp2
I never have any bumps.
Fraps is VERY hard drive intensive, you need a good performance RAID array or SSD to record full-frame size at a high FPS or you run into bottlenecking issues. I personally record onto a 5x2TB RAID 5 array of 5,900 RPM drives with a sustained write speed of something like 110 MBps (not Mbps), it wasn't a cheap setup though.