According to Wikipedia here are the twenty top grossing films of the decade...
1. The Lord of the Rings: The Return of the King
2. Pirates of the Caribbean: Dead Man's Chest
3. The Dark Knight
4. Harry Potter and the Philosopher's Stone
5. Pirates of the Caribbean: At World's End
6. Harry Potter and the Order of the Phoenix
7. Harry Potter and the Half-Blood Prince
8. The Lord of the Rings: The Two Towers
9. Shrek 2
10. Harry Potter and the Goblet of Fire
11. Spider-Man 3
12. Harry Potter and the Chamber of Secrets
13. Ice Age: Dawn of the Dinosaurs
14. The Lord of the Rings: The Fellowship of the Ring
15. Finding Nemo
16. Star Wars Episode III: Revenge of the Sith
17. Transformers: Revenge of the Fallen
19. Shrek the Third
20. Harry Potter and the Prisoner of Azkaban
Kottke.org noticed that of these films only 'Finding Nemo' was based on an original screenplay. All others were based on existing material - adaptations, toys or sequels/prequels. Now this isn't new - 'Gone with the Wind' was based on a book as was 'To Kill a Mockingbird' and 'The Godfather'. 'Casablanca' was based on the play "Everybody Comes to Rick's". 'Rear Window' was based on the short story "It Had to Be Murder". Adaptation is not a new phenonenon. There is a lot to like in that top twenty list. Yes, they are popcorn movies that appeal to the masses - that's the idea. That is why they are the 'top grossing' and not the 'best films of the decade list'.
The only problem with this list is that it solidifies the Hollywood bean counter's idea that these are the only films to make. It creates homogeneous film industry that spews out the same films over and over.
I think the solution to the problem is to let them keep doing it. Why? Because they are going to exhaust their catalogue of sequels and book rights. The well will run dry and they will have to start to look for new material. I think we are coming to a time that reflects the end of the 1960's where the studios lost touch with the audience and faltered. They fell apart and the pieces were picked up in one of the most daring and original decades of film.
Independent film has waned over the last few years and one look at Apple's Quicktime Trailers site shows an industry in confusion and flux. The future is uncertain, that is for certain. People love movies, that is also for certain. It's also a historical fact that Hollywood has been doing adaptations and sequels for a long long time. Andy Hardy anyone? Sixteen movies (granted before televison). Sergio Leone's 'Dollar Trilogy' was an unofficial remake of Kurosawa's Yojimbo.
It is not a new phenomenon, nor is it a bad thing. Adaptation has given us some great films.
As for original films... What do consider the greatest?
Ace in the Hole.
North by Northwest.
On the Waterfront.
Through a Glass Darkly.
La Dolce Vita.
2001 A Space Odyssey.
Do the Right Thing.
The Three Colors - Blue.
(and so many more...)