First Edition of Where the Wild Things Are
This 1963 children's book has been adapted numerous times, including a recent 2009 film adaptation by Spike Jonze. In total, Where the Wild Things Are has sold over 19 million copies worldwide. A first edition of the book signed by the author and illustrator Maurice Sendak is worth $3,176. Even an unsigned first edition can go for $50.
Mighty Max Playsets
This 1992 toy series was similar to Polly Pocket, except it was marketed toward young boys. The toyline mainly consisted of "Doom Zones" and "Horror Heads." While the individual toys aren't incredibly valuable on their own, playsets receive the highest market resale, often going for a few hundred bucks.