By thinking how they would do him I'm expecting a really evil yet elegant villain(the only one i can see like this thus far is Adagio). I was thinking who would be good to voice him and two people came to mind.

-David Kaye mostly because of this:

-Ron Pearlman:

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Aside from David Kaye as well, I would also love to see Michael Dorn (Lt. Warf from Star Trek: TNG) to voice him.

5918560 While that version of Megatron is intimidating, it feels too obvious to go with a main villain from another series Hasbro own. Plus I kind of don't want the fans to pull instant comparison with two very different villains.

Now Ron Perlman can work under the right conditions could pull a young version of Grogar. But the previous version was incredibly old. I kind of doubt they change his age just to sound better with the actor's voice. Ron Perlman indeed old himself but every role he has taken makes him sound like a guy in his twenties-thirties. I'm not saying he couldn't pull it off I just have my doubts. Though he is a better choice the other one.

5918693 I could see Warf's actor pulling it off simple for the voice but I would have to see him in other roles first or I'll keep thinking that Grogar should be talking in Klingon.

Meanwhile, my choice will always John Noble

Both intimidating and wise. From his role in Fringe to his current on and off roles on Sleepy Hollow. He has shown to be both things that Grogar is most known for. Plus he is one of the few actors that would still sound intimidating when pulling off Grogar famous growl.

5919090 He really sounds good for him.

5918560 I've always felt like if Grogar was depict as a High Level Threatening foe, he should have a voice that makes him sound Serious, Evil & kind of Scary,

With someone like Kevin Michael Richardson, mostly due to his portrayal of Trigon from (The Good)Teen Titans series:

Or even someone like Jim Cummings, using the same voice he used for the Marvel Comics villain known as Ghost: