This is a sort of two-part topic.
1. What are your favorite anime dubs in general?
2. Do you have any specific English VAs you really like?
I'll start I suppose.
Hellsing Ultimate, yu Yu Hakusho
Yuri Lowenthal - He is probably best known as Sasuke in Naruto but he is also Pip in Hellsing, Kevin in the third Xenosaga game and a ton of other roles.
Mary-Elizabeth McGlynn - She is the voice of the Major in Ghost in the Shell: SAC as well as Nuriko in Fushigi Yuugi.