I don't think you can have a discussion of this sort without including some form of organizing and rating your own images. The two best pieces of software I've seen for this are Adobe's Lightroom and Apple's Aperture. I have six categories when it comes to rating my images. Unrated, and 1 thru 5, 5 being the top category.

I do backups every six months. Those images that are rated 4 or better go to online storage. Those that are rated 3 or better go to offline external hd storage.The Raw files that aren't deleted (1 or better) go to DVD backup. Those that are unrated are deleted.

- Joe U.