Fraps takes screenshots and videos in game. It also does benchmarking. Just go to the website (fraps.com) to see the full feature list and you can d/l the demo there too.
There is GameCam.. Thats Really Cool... I Had some Bugs from it Though... Like Halo Wont Open.. But Game Cam is MUCH Better.. Fraps you Can only make 30 seconds Video's or Buy the Full Version.. GameCam You Can Record as Long as You Want
I use fraps, I did use Game cam, but the interface interfered with my gaming too much. Beside I don't really need to record really long movies, 20 seconds max.
When I'm recording something I use the same thing I used when I used to make video tutorials on another site, Camtasia. I like it better than anything else I've used. Plus, after you start it, it tells you the buttons to start recording and to stop recording, then it runs in the background, just a little button on the right of the taskbar, whatever you call those. Camtasia Studio can be found here, just click on the Camtasia Studio download link. It's only the trial, which is 30 days long(if I remember correctly), but for you smart people...there are ways around that. I won't name those ways since it would be considered 'illegal'.