No stranger to large, powerful, stern, stoic, commanding, government-esque or military leader characters, Garry Chalk was tasked with bringing Forge to vocal life for his first appearances in the franchise. When Forge becomes a part of the story in the direct-to-video movies, he's hired as a replacement N-Tek leader, and boy, he's there to do business. Strict, calculating, no-nonsense, he has very little time for Josh McGrath's insubordinate behaviour and attitude. He eventually warms up to Josh, but still maintains the firm, authoritarian attude.
Michael Dobson was cast as Forge in the 2013 rebooted series, where Forge is still more-or-less the highest-ranking officer at N-Tek, but is also now Max McGrath's uncle. With that, there's obviously more of a friendly relationship between him and Max, even though Forge would still stop at nothing to protect Max and defeat evil. While Garry's voice is more "military leader", Michael goes for "heroic superbeing" kind of voice.
Yet again, a very tough choice. They don't come much more "commanding authoritative figure" than Garry, but Michael also does a great job while bringing more warmth to his version of the character. It's a tie, since they're both so fantastic in the role.