As I've said before, the Hanna-Barbera Cinematic Universe needs a Space Ghost! While it should definitely be based on the original cartoon, with Jace, Jan, the monkey, etc. etc... you'd be remiss to not acknowledge the Coast to Coast and Cartoon Planet version voiced by the hilarious George Lowe.
That was the Space Ghost I grew up on and it's certainly iconic. If the big guy ever actually does make it to the big screen, I think striking a fine balance between the two versions would be to everyone's advantage.