Aside from the obvious one of video games, there's also comic books (I haven't counted in years but to say it's well into the thousands might be an understatement), snare drums (or drums in general), cymbals, and occasionally action figures and toys. Those are the big ones I think. I suppose there were heroclix figures when I was still playing a lot, and now Warhammer 40k models since I took that up, but I'm planning to sell a lot of the former, and really only have the latter because I enjoy the game, and am enjoying customizing and converting models thus far. It's not so much that I want to collect them just for the sake of it as it is they facilitate my enjoying other aspects of the hobby.