[ActionAndy]

Well you've kinda rigged your poll by asking a different question than your actual focus! Your focus seems to be what makes a voice memorable and interesting to listen to--but your poll asks which is most "attractive." Peter Cullen (Optimus Prime) obviously has a very distinct delivery, but I can't call it attractive...

Edit: Re-read your last line, now I see the reason for the distinction. I'll add Rocky Balboa to the list of unmistakable voices.