Teach me your ways...

I've always been good about archiving my digital stuff, but only just recently have I had the issue of all of my crap not fitting on a single drive.... Documents and pictures haven't been much of an issue, but having gotten into the habit of backing up all the blu-rays and modern games I own, your average hard drive isn't cutting it anymore...

So what are the most cost effective/space saving/convenient methods for backing up all of your shit?