These days I tend to go and buy another external hard disk when I need space...wait for a bargain in a sale.
If I want to do anything with movies I tend to use TMPGEnc Video Mastering Works 5, though they are on version 6 Version 6
This is because I've used the product for ages and I'm used to it.
Wondershare Video Converter Pro has editing capabilities but I really use it for other stuff. These are both 'paid for' programs.
There are dozens of programs available. My advice is to try some, find one that does what you want simply and stick with that.
Not sure if Windows Movie Maker
is still around but I seem to remember it was a basic program. I think you have to get it as a package these days