... Starburst (the candy) wrappers. I have a bajillion wrappers so I can make stuff like rainbow bracelets and other random things. I want to eventually collect enough to make a purse but that would require hundreds of wrappers.
Comics, specifically those that have the Scarlet Witch and Quicksilver in them. Once upon a time I used to collect Barbies (of the collector variety, not the kid ones) and anything with unicorns, but I don't really add to those collections anymore.