JCC for sure. Here's my list of fighters I'd like to see documentaries on.

Stan Ketchel,
Benny Leonard,
Charley Burley,
Carlos Monzon,
Kid Choco,
Ezzard Charles,
Lamotta, Graziano, Tony Zale
Arguello,
James Toney for sure

I'm not going to include the guys that already have significant documentaries on. I've seen one's on Pacquiao, Emile Griffith, Marciano, Dempsey, Robinson and other big names.