I've gotten rid of much of my stuff and I don't really collect. I suppose there are some things I'll never get rid of and do actively want to expand on like my Dreamcast library though.

A good friend of mine is something of a collector, as well as someone with an unnatural talent for making a profit buying and selling games, many of them rare collector's items in and of themselves. The major stuff he's into collecting for himself now though is PC-Engine games (and systems sort of since he stumbled his way into owning several this fall), and arcade boards for some rarer games that also happen to be amazing. We had a hell of a fun time playing a lot of his stuff when he was visiting for a few months this fall.