Would make a great Spike Spiegel
He may be slightly taller than the character, but he's got the charisma, "devil-may-care" look and the acting range and can pull off Spike's sensible side and "tortured soul" vibe.
Lee is a great actor and fairly overlooked, did a did well in GOTG, but I think he could demonstrate his acting chops as a lead on Cowboy Bebop.