Camtasia is a good but not great product. I never found a recording tool that satisfied all my needs. I would say that Camtasia has excellent editing tools. I edited the videos i recorded to cut hands without action.
My problem with camtasia is that it seem that it re-codes the video again after edition and the quality drops significantly.
Camstudio is free but its not as complete as camtasia. There are some free editing tools you may need to download to use with it but none is user friendly.
Wink is another free option,
http://www.debugmode.com/wink/ but it recods on flash video only.