My favorite VA is Tamura Yukari. She was the VA for Jibril in No Game No Life and quite a few other shows as well such as Absolute Duo, Akame ga Kill and many many others. Her voice is just so nice and soothing to listen too, especially when she's signing.
I don't really lookin into voice actors much usually, but I like Gavin Hammon and Melissa Hutchison. (Voices of Kenny and Clementine in TWD games.) Both are very good at what they do and both seem to be very nice people, spoke to Gavin on ask.fm a few times like a year ago.
EDIT: I just re-read the OP and realised you meant in Anime, which I don't really watch so uh..Just ignore this.