Obviously a Windows question. I have my preferred ones for Mac OSX because the choice is much more limited. I know which ones work well for me and since I am doing frequent back ups for later viewing, the ones that almost always work I stick with. There's a few back up utilities just in case.
Best share outputs would probably be DivX or H.264 which seems to be a little better than the previous. But not everybody has H.264 codecs yet on their system.