100 Great Film Performances You Should Remember--But Probably Don't by John DiLeo (2004)

There are a million books on the best films, but the great thing about this book is the focus on the actors' work.  The author outlines each performances (from gesture to expressions to line delivery) in great detail, with great enthusiasm. It's like going to the movies with DiLeo himself, and great fun.  Full of underappreciated gems, this is a total treat for movie lovers.