I buy anything and everything on eBay. I mean *everything*! There are still many great deals to be had there, as long you're not always shopping for the hottest item out there. "Think outside the box" as they say.
Computer & electronic components, car stuff, a slightly used Dirt Devil vacuum (paid $5 + change, works like it'* brand new), DVDs of course, PS2 games, also sold the same although selling is somewhat of a hassle and I don't do it too much. Occasionally I've bought clearance items from retail stores, then sold them on eBay for a nice little profit.
I've also bought various stuff for work (that I later deduct on my taxes), clothing for myself, my wife, & kids, tons of books (check out half.com too) and so many other various things that I've lost track. 250+ auctions I think, and most of that is buying. Go EBAY! :P