I used to buy any Disney pin I thought was cute, but that was going to be major trouble.
Now I only collect pins that have Uncle Walt on them.
Like @jynxiie, I like ornaments. I have a lot of Christmas decoupage ornament collections from the various years, as well as a few sculpted ornaments.
I just starting collecting Disney Itty Bittys from Hallmark, and I have Disney plush from Build-a-Bear.
Disney t-shirts, although I recently cleared about 1/3 of them out of my closet (sad but true, but some of them just had to go).
I've got a LOT of Disney books, everything from The Art Of and history books, to picture books and chapter books. I used to collect the Read Aloud storybooks, but they don't make those anymore, so now I buy the Big Golden Books instead.
Of course, Disney soundtracks, because DISNEY SOUNDTRACKS.
One of my favorite things is odd-ball Pixar characters, which I define as characters who don't normally get to be on all the merchandise. I have a small bookshelf dedicated to Pixar, and I've got a Dolly plush from TS3, the same Big Baby figure that director Lee Unkrich has, and a Hamm bank, whom I love feeding coins too.