I think Camtasia 7 is free, if not; Try Fraps
They have fraps, but some of them use dxtory and have fraps as a backup.
I prefer Bandicam...but some people do like Fraps. it is really your preference.
Fraps!
Fraps is far more advanced but it's not free and the free demo version of Fraps places an ugly watermark on the video. I guess Camstudio would be the best free alternative around. Try that first and if it does not cut it for you, then obtain Fraps in one way or another.
They use software called FRAPS
If your playing on a PC then check out software called Fraps
Fraps, or HyperCam
Well, if you have a Mac like me, you should use Screenflow by Telestream ($99.99) or if you have a PC, you can buy Camtasia, Fraps, or Action! software. I've heard fraps is good, so I recommend that.
fraps but its not free...
d3dgear, bandicam, xfire of fraps
You can download fraps for free and make thirty second videos with a fraps.com watermark at the top center. Or you can buy the program for 37 USD and get free updates.