Mystic River (2003)
Directed by: Clint Eastwood
Written by: Brian Helgeland
Based on: Mystic River (2001) by Dennis Lehane
Why it’s better: Dennis Lehane is an excellent storyteller, which is why he’s so often adapted. But his stories tend to play better onscreen than in print, and Mystic River is the most notable example: The film’s powerful performances (led by Sean Penn, Tim Robbins, and Kevin Bacon) add a level of depth and emotional resonance lacking in the novel.
The movie sucked
#25... I don't think better as such, but more so, brilliantly capturing the true essence of the books, yet Mr Tom bombadil is much missed
The movies are weak on it's own, but they are crap adaptation. It's plastic-cheap game cutscene-level, which is way more obvoius when you (try to) watch The Hobbit.
Overall you have very little idea on what makes movie better than book. Cutting things and simplyfying plot does not make them better story teller.
About the other books and movies that I've read and watch:
Godfather:
Both movies are great on it's own but it does not make them better than books.
The Prestige:
The book seems to be good until finale which is crap.
Movies are typical Nolan-like pulp, he's crappy storyteller.
Jurassic Park.
Movie is great on it's own, but book is much wider and Spielberg have to cut good part of it to make reasonable size movie. Other plots were included in part III.
As for Starship Troopers (I didn't read the book) - the movie was dumb. Satiric tone was nicely made (as Verhoven did in Robocop), but the rest was huge pile of crap.