Uhhh, my Xbox and PS2 and games? Pretty boring, I know, but they are valued possessions.
A painting that I got my mother for her birthday, it's hers, technically, but I value it too (I did spend $225 on it).
Some pieces of artwork I've made myself - a big charcoal self-portait, a pastel coastal landscape drawing, an abstract magazine clipping and mod-podge piece I made, probably some others I can't think of at the moment.
Some of my dvd's, not all of them. But definitely stuff like the Firefly set, seasons 1 and 2 of the Venture Bros., The Amazing Screw-On Head pilot, others I can't think of. And btw Hey Joe, props for the massive collection. My own is like, no more than one of those shelves, if that.
My plush headcrab!