I have too much to list without doing an inventory. Albums, singles, vinyl, CDs, posters, promo crap.... My favorite items are the 7" & 12" vinyl and 3" & 5" CD singles I've collected, both commercial and promotional. They are the heart and soul of my collection.
The CDs are packed (I'm moving soon) and the vinyl would be packed if I hadn't left it out to listen to while packing.
Once I get moved, I'll put it all in a big pile and take a picture.
There's a wonderful message board for Depeche Mode collectors, called DepMod, and you should see the photos these guys post of their collections - it's CRAZY. They will buy every album and single, in every format, from every country in the world where it is released - commonly resulting in dozens of copies of each item that have no differences other than barcode or CD matrix number. These are collections that have their own rooms!