New York Times Film Reviews- Search Proquest Historical Newspapers online to find the full text of reviews from 1857- 2007. More current reviews, 1980 - current, are found in Proquest National Newspapers.
Proquest Research- includes Time, Newseek, New York Times Magazine, Vanity Fair, People, Us Weekly, Entertainment Weekly and many other popular magazines with film reviews.
Rotten Tomatoes- has links to popular reviews