The Blockbuster Entertainment Guide to Movies and Videos 1999 is THE BEST movie reference guide I've ever had. Unfortunately, I haven't been able to find an updated version in the last ten years, so it isn't as up-to-date as it used to be.
I have tried some other guides, but this is my favorite. I like the comprehensive set up of this guide. It's designed like an encyclopedia and has "over 23,000" entries, with small blurbs for each movie. It also includes director and actor filmographies indexes in the back of the book, and a special section for children and family recommendations.
I've read it cover-to-cover twice, although I do debate some of the ratings, most of the reviews are fair and accurate. Every once in a while I ran across reviews where it seemed like the reviewer had a particularly long day, along with at least one reviewer with a sense of humor, and a stockpile of bland and questionable adjectives such as: simple, uninvolved, bucolic, subtle, uneven, predictable, charming, painless, insignificant, mindless, entertaining, sprawling, masterpiece, breezy, overdone, and descriptions of attractive and likable casts, and categories labeled character study, soap opera, and comic drama.
I plan to save some of these adjectives for my own future reviews. ;)