Antonio Brown
Here is one of the wackiest stories on this list because it was one of the worst trades of the past decade. Everybody knows that Brown is a volatile character but a brilliant footballer. He signaled that he wanted to leave Pittsburgh and this was enough for Jon Gruden to pursue him. The Raiders gave up third and fifth-round draft picks in exchange for the wideout.

But he never played a down for the team because of a bunch of off-the-field problems. Brown notoriously froze his feet in a cryogenic chamber; of course, he did. He also missed practices and went head-to-head with GM Mike Mayock. The Raiders released him before the first snap of the season (via Wall Street Journal).