Note: Current as of November 10, 2011. This only counts movies with at least 25 ratings and the actor in a decently-sized role with some tweaking. Thanks to skishua for the inspiration.
Rotten Tomatoes compiles ratings and reviews from professional critics who have published their reviews. Because of there are more reviewers now than there were in the past, their rankings tend to favor movies of the last decade or two and animated films.