I just got some more links from Tobi (thanks again). Radical Entertainment, a very well-organized developer in Canada, cooperated with the Computer Science department of the University of Calgary for a computer game programming course. As part of the course, they provided various game documents from their titles: game designs, high concept documents and technical game designs for titles such as Dark Angel, The Hulk, etc.

I added the info on where to get them to my earlier post.