18. Kellen Winslow Jr.
Winslow was one of the most dynamic offensive weapons in college football during his time at Miami. So when he was drafted by the Browns there was hope he could lead Cleveland to success.
Instead, he practiced tricks on his motorcycle until one day he hit a curb and tore his ACL. He missed the entire 2005 season. What’s worse, Winslow had a clause written into his contract forbidding motorcycle riding. What a selfish act that cost both his teammates and his fans.