Amazon has the The Polar Express (Widescreen Edition) marked down to just $6! You can watch it instantly on Amazon Instant Video after you purchase it.
Or you can get it on The Polar Express [Blu-ray] for $8.99.
This is one that we watch every year. I finally ended up buying it to add to our “holiday faves” collection.
Remember, prices flip fast on Amazon so be sure to verify the current price before purchasing!