A couple of weeks ago I heard Tom Waits' distinctive voice over a commercial on Hulu and immediately drew my attention because it was entirely unexpected. The commercial is a PSA for Feeding America. I now understand why Tom has chosen not to dilute the effect he gives the commercial by also shilling for Pepsi and Chrysler.
In the deep dark past there was this one commercial for Purina though. I find his intonation hilarious.