In addition to Thundercats, I also vote for a classic WWF/WWE line. Ya know, the 80s flashy wrestlers that made it what it is now. The Golden Age that made it an institution. Make Hulk Hogan, Randy the Macho Man Savage, Jake the Snake, Ultimate Warrior, Koko B. Ware, Andre the Giant, Iron Shiek, Junkyard Dog, Ricky the Dragon Steamboat, Brutus “The Barber” Beefcake, Rowdy Roddy Piper, Honky-tonk Man, Mr. T, Big Boss Man, Hacksaw Jim Duggan, The Road Warriors/Legion of Doom, Ax and Smash/Demolition, the Bushwhackers, Bam Bam Bigelow, George the Animal Steele, King Kong Bundy, Zeus, “The Million Dollar Man” Ted DiBiase, Akeem, umm... I am probably missing someone (sorry fans,, surely you have a fave I forgot. I deliberately didn't put the non-gimmick, regular names guys)...
Include gimmicks and obvious accessories
(you best not include a boa constrictor with Jake the Snake, and barber tools with Brutus, and Koko's parrot, etc).
I would even be down for the supporting cast like “Mean” Gene Okerlund and Miss Elizabeth or other managers, etc.
Then you go to later era and bring in The Undertaker, Sting, Goldust, the Rock, Goldberg and into modern times. But hold off on these and the ladies unless part of Classic Era like Elizabeth.
You could do just Heroes, minifigure releases, and then a ring set build, cage match build, etc. Maybe include announcer/manager/tables, etc in sets. These being exclusive to sets would drive sales alone. WE LOVE OUR MEGA CONSTRUX MINIFIGURES!!!