Rena 'Sable' Mero
'Superstar' Billy Graham
Bret 'Hitman' Hart
And many more.
You can now add CM Punk to this list.
All of the above had issues with the WWF/WWE over the years. Some went so far as a courtroom battle and ALL have returned in some form or fashion.
Punk is the latest, He made his 'return' to WWE screens last night at the conclusion of WWE Backstage on FOX Sports.
Word is he's not technically signed to a WWE contract as the deal is with FOX. Still, he's working on a WWE project.
Even if you want to be pedantic and simply call it a return to working within pro wrestling.
It's a comeback...