The Terminal Man was one of the best books that I had on the school reading list in the early 1980's. I stayed up all night to watch the movie on a station that we barely received (way before we had cable at my house) and was really disappointed. They really blew the ending in my opinion. It amazes my why filmmakers change important parts of a best selling book. Had it been written to match the movie, few would have bothered reading it.
Jurassic Park is one book where I liked the movie way better as it's special effects really complimented the dinosaurs and left out the parts about the T-Rex swimming after people.
Twister, Rising Sun and Andromeda strain were all better books than movies in my opinion. Crichton rocks!