I still haven't seen a bunch of movies released at the end of the year (The Good Sheppard, The Pursuit of Happyness, Rocky Balboa, Dreamgirls, Pan's Labyrinth, The Queen, Volver, Notes on a Scandal, The Good German, The Painted Veil, Bobby), and I missed a bunch of movies that were well-reviewed (Wordplay, The Devil Wears Prada, Half Nelson, The Last King of Scotland, Little Children, The History Boys, The Illusionist, The Science of Sleep). But based on what I have seen, here are my 10 favorite movies of 2006 (in alphabetical order):
Casino Royale
Children of Men
The Departed
An Incovenient Truth
Inside Man
Jackass: Number Two
Little Miss Sunshine
Mission Impossible III
Thank You For Smoking
United 93

And my five least-favorite movies (also in alphabetical order):
Basic Instinct II
Clerks II
For Your Consideration (just because it was SUCH a disappointment)
Grandma's Boy*
Nacho Libre

* Even though they're listed alphabetically, this is unquestionably the worst movie I have seen this year, if not this century.