G.I. Joe
Every young boy in the 1960s had one of these guys. The name "G.I. Joe" references the generic U.S. soldier; the G.I. Joe also led to the coining of the term "action figure." With such an important history, it's no surprise that a mint condition original 1964 G.I. Joe is valued at $10,000.
First Edition of Harry Potter and the Sorcerer's Stone
At first, J.K. Rowling couldn't even find a publisher for what has now grown into the most popular fantasy series around. If you picked up a first edition copy of the series' first book, it could be worth $6,500.