Do you have a Frozen fan in your family? We've watched the movie a few times in my house and if you ask any teachers what song they were tired of hearing last year, I'm sure it was "Let It Go". This movie is still very popular.
5 Below has Frozen merchandise that you might want to grab now for birthdays or Christmas.
The link above will take you to their page where they list their products. Not every store will carry the same merchandise, so you may need to visit more than one store to find what piques your interest. There's lots of little things for stocking stuffers on the cheap, or if you have a themed birthday planned, you can stock up on plates and napkins and other things for a goodie bag.