Speaking of Screwtape The absolute best audiobook I've ever heard was John Cleese's reading of The Screwtape Letters. Cleese has the perfect voice and attitude for satire, and at times makes Lewis's work laugh out loud funny.

The absolute worst audiobooks I've heard are the Roddy McDowall readings of L. Ron Hubbard's works. McDowall manages to drain absolutely every speck of life out of everything he reads. And considering how loquacious Mr. Hubbard can get--I must admit to never even having managed to finish an abridgment.