Jurassic Park T-Rex
Jurassic Park's recent comeback via the Jurassic World reboot has made the franchise even more popular, meaning that merchandise from the original films is now considered collectible. If you have any toys from the original Jurassic Park era, look for the Jurassic Park Lost World Series One Thrasher Tyrannosaurus Rex—it recently sold for $900 on eBay.
Pokemon Cards
Pokemon cards were once all the rage, and their popularity has been steadily rekindled with the development of Pokemon Go. First edition cards from 1999 to 2000 are worth the most amount of money. For instance, if you happen to find a Pikachu Illustrator Card laying around, you just scored $100,000—but some cards, like the First Edition Shadowless Lightning Energy, might only sell for $1.