Joshua Drake has been using Linux professionally for over 10 years, and he shares his opinions and comparisons in an admittedly subjective but thorough comparison of the five major Linux distros for "non geeks." The comparisons are between Red Hat ES, Novell SLES, Fedora FC4, OpenSuSE 10, and Ubuntu Breezy Badger. Again, this isn't exhaustive, but it's a quick read, especially if you know someone considering Linux, but they don't know which "Linux" to pick.