I quite liked the voice actors from D:OS (the classic one, that is) and Ego Draconis: I guess I'd rather stick with them than the big names, where I can't help feeling I'd hear Emma Watson and Morgan Freeman rather than the characters they're playing. Well, that and A-list actors tend to charge a large fortune to do any voice work.
The voice acting in ED was a big step up from DD amd BD, the latter of which gained a certain amount of notoriety...