Despite having already proven his superhero bonafides as the voice of DC's Green Lantern in multiple animated projects, and as the voice of one of the interstellar inmates in Marvel's "Guardians of the Galaxy," there is still plenty of comic book-based characters who would be a perfect fit for Nathan Fillion -- and the actor knows it.

At last weekend's Wizard World Comic Con Chicago, Fillion responded to a question about what character from the Marvel or DC Universe he'd like to tackle next.

"I think I could take a pretty good crack at Booster Gold," Fillion responded in video shot by ComicBook.com. "That's kind of my niche. Show-offy, vain -- I think I could handle that. Not too bright. I think Ambush Bug -- you know that guy? Little bit off his rocker, you'd never see my face."

After broadening the question to look beyond Marvel and DC by offering that "'Greatest American Hero' is due for a reboot," Fillion turned to his "Firefly" castmates, Summer Glau and Adam Baldwin, and posed the same question to them. Glau responded with "She-Ra," while Baldwin answered "I don't know. Green Lantern?" to Fillion's mock disapproval. "It's already taken, yes -- by me!"