This is a real tough one for me

For Optimus anyway, I prefer Kaye as Megatron. Something about his voice to me seems very...diabolical, as oppsoed to the sinister...ness, of Welker's Megatron. Welker still did a damn good job, though.
No, the problem for me lies in the choice of Optimus. I grew up watching Beast Wars and all the Transformers that came after it, so he was my prime for a while. However, in light of the movie coming out, I have started watching more G1, and really enjoy Cullen's voice.
Chalk: Was like the battle-ready father, one who commands respect by leading you into battle and saving yer robotic ass.
Cullen: Like a wise Grandfather/Uncle figure, one who you respected not because of his actions, but because of his honest words. You actually felt for the Transformers when he died.
So...damn