I use fraps, which you can get the free version at download.com. Only problem with the free version is it cuts out oafter 30 seconds of recording. Also the fraps name will be on top of any recording you take. If you buy it, you have unlimited recording and no fraps logo. I then go to windows mediamovie maker and edit it there, adding music. Ive made a few from WoW with some guildies and two from EQ2, just putzing.
A few exanmples of some of the vids I've made:
Wow Bohemian Rhapsody WoW "Monday" EQ2 "Specter Stomp" EQ2 "Bring Me to Life" The third vid takes awhile to load. My apologies