Personally, I prefer Fraps. You'll need a program to edit and compress the video, because you'll get massive uncompressed video files... but it gives you the most to work with out of anything. You can take any level of quality and go down. You can't exactly take a low res video and just make it better somehow.
For perspective, an hour of video can be like 200 gigabytes or more. If you haven't got the hard drive space, look up Camstudio, or I'm sure someone else has a better one.