Captain America sleeping bag.
Darth Vader bedding.
Reusable snack bags with Spider-Man, Batman or Star Wars.
Since its Pottery Barn, it is a little pricey. But I think if you're buying the bedding (or anything that's going to get a ton of use), its well worth the price. And since its the holiday season, they're having some sales on their website, so you might catch a great deal :)