EDITOR'S OPINIONFirst off, I can't deny any credit to Walt Disney, both for creating Mickey and his iconic voice. He actually makes for a pretty good voice actor! Bret Iwan also shows promise, and seems like he's shaping up to become a natural in the role. Like many of you, I grew up listening primarily to Wayne Allwine's take on Mickey, and I feel he sounds most natural in the role. James MacDonald and Les Perkins are also pretty good, but IMO not quite as memorable as the others. As for Chris Diamontopoulos, his imitation is a little closer to Walt Disney in terms of pitch, but it's not quite as lively as I'd like.
In the end, I'd say Wayne just barely edges out Walt, with Bret Iwan in third place, followed by James McDonald in fourth and Les Perkins fifth.