4. Sting (2015)
It's hard to believe it's been five years since Sting's first-ever WWE match. Sadly, we're also rolling up on five years since Sting's *last* WWE match, as well as last match anywhere, as a result of an injury sustained in a WWE championship match against Seth Rollins.
Rollins delivered his patented Buckle Bomb onto Sting late in their title bout, resulting in the 56-year-old icon sustaining cervical spinal stenosis, which required surgery to fix. As a result of the injury, Sting officially announced his retirement the following April.