The XBox HD DVD drives are flying off the shelves. Obviously, watching your fave movies is what you really care about. But if you're looking for a disc that shows off the HD DVD format's interactive capabilities, Tokyo Drift is the best example out there. It's that or Miami Vice. Seriously.
While we can't vouch for the film itself, we can verify the disc's extras are amazing, including full storyboarding, technical specs on all the cars, GPS mapping of all the chase scenes, and the ability to watch some parts of the movie with repainted cars:
The entire movie's story boards can be switched on over the video.
The movie's makers worked with Progressive Auto Insurance to estimate the cost of damage done to the cars. 
Picture-in-Picture
A car's tech specs will flash on screen occasionally.
And the picture-in-picture is actually a separate datastream, which goes to show off HD DVD's extra video decoder (it's part of the spec, and no Blu-ray drives currently ship with a second decoder.)
And the disc's FF index, like all HD DVD movies, shows the time remaining.
The producers have set up a little animation that can be turned on during car chases, highlighting the path the cars are taking through Tokyo. (Fictionally, since a great deal of the chases were done in LA.)
And you can bookmark your favorite scenes, like this one.
The main characters do a smokey burnout trying to impress some girls at a stoplight.
Instead they impressed me. Perfect circle! If I could drive like that, I'd blog for Jalopnik.
(Spoiler: They get the phone number)
Now, going into the special features section of the disc, you can repaint the car, and give it all sorts of ricey details.
And watch the scene again, with the car you just created.
Is the movie shit? I don't know. I kind of like it. But the movie's extras go a long way to showing off HD DVD's capabilities.
