Kaley Cuoco certainly wore the outfit better than Jim Parsons’ Sheldon, who was forced to wear the outfit after losing a game of bowling to Wil Wheaton in Season 3.
To be honest, Penny’s Wonder Woman is definitely the best costume we see in the episode, with Zack’s Superman costume a close second.
The wigs are different between the two appearances, but the outfits are similar enough that I wonder if they both wore the same costume?
Obviously, this 2010 Wonder Woman costume looks more like the Lynda Carter garb than the modernized suit Gal Gadot rocks in the film, so it’s kind of unfair the judge the two on who wore it better.