3. Ric Flair (WCW, 1991)
Maybe you've heard (Herd?) of this one. After numerous run-ins and disagreements over contracts and the like with imperious WCW VP Jim Herd, Flair was fired from the company two weeks before the 1991 Great American Bash - while still reigning as champion.
This caused a public relations nightmare for WCW, as Flair (in possession of the belt) shipped the strap to Vince McMahon up north. He later debuted for the WWF with the gold, proclaiming himself to be the "Real World's Champion". Herd resigned from WCW weeks into 1992.