I made 40GB of bad video recordings. Now I need to remove the bad parts without wasting too much time. Is there a video editor, preferably free, where I can hold a button while the video is playing and automatically mark that section as something to keep or delete from the video?
They are free and you should be able to do what you want. I don't know if you will consider them simple.
VideoRedo is simple but costs money. http://www.videoredo.com/en/index.htm www.videoredo.net/helpdocs/en/plus/pdf/PlusHelp.pdf
Read pages 12-15 for keyboard shortcuts. If you need to trim the beginning simply find the end mark it, and hit cut. Otherwise, mark the beginning then mark the end, and then click cut. When you are done cutting just save it in the original format and your done.