It doesn't matter to me whose face is at the other end of the voice I'm hearing. As the father of a five year old I get to hear a lot more cartoon voices than a lot of you might. But it can be fun sometimes to hear the voice of "Clifford the Big Red Dog" and realize it's John Ritter - or hear the voice of his next door neighbor and recognise the voice of Tom Bosley.
Commercials are a different matter. LOTS of actors doing those for extra cash. Gene Hackman among others.