I'm kind of surprised that I didn't see it mentioned here yet, but he acted really well in Command and Conquer: Tiberian Sun. His character there, General James Solomon http://cnc.wikia.com/wiki/James_Solomon
actually has many parallels with Mufasa.
You kind of see a warm gentle giant in one short clip in the intro when he says "good to see you again, Mac". But for the rest of the game, you get the kind of person you would expect someone like Mufasa to be in a war: No nonsense, get to the point, get the job done. The way he wasn't intimidated by Kane 'coming back from the dead' was just awesome on all counts. I have a blast whenever he appears on the screen. Even in the "bad guys" Nod campaign.
General Solomon = Mufasa.
James Earl Jones = Made of pure Awesomeness