Keeping track of my vids...

I am looking for some advice on how best to archive my vid collection on my G:drive. I really like wmv files because they allow me to edit a vast amount of property tags and make it easy to sort/search my files by vidder/fandom/song/band etc. Unfortunately many vids come in formats that do not support property tag editing, and conversion into wmv causes significant quality loss.

So, my question: What do you guys do? Has anybody come up with a good way how to archive vids? Are there any other ways to tag vids? I'm grateful for any ideas....