Should I use screen capture software or video camera?

I want to make short videos that capture what I'm doing onscreen to demonstrate how to use different sofware programs like Open Office, etc. I've not only watched a ton of these types of videos on YouTube, but I've tried out Camtasia and several other full trial version screen capture programs that people have recommended. In my opinion, the quality of the videos made from these screen capture programs sux donkeys. I can barely even read any of the text in these videos. Does anyone know if it might work better to buy one of the high def video cams, set it on a tripod in front of my computer screen and record the screen action that way? Has anyone reading this done this or heard of anyone that has done this? To reiterate, the videos I've seen made with the screen capture programs is horrible quality.