A thought occured to me and I did a bit of research to try to back it up, but as it turned out it's rather backfired on me....
Looking at the International Box Office recorRAB we see:
1. Titanic $1,845.0 million 1997
A film about a Brtitsh ship sinking. If memory serves the main 'villian' of the film was American.
2. The Lord of the Rings: The Return of the King $1,118.9 million 2003
A film based on a novel by a British writer, predominantly starring British actors.
3. Pirates of the Caribbean: Dead Man's Chest $1,065.7 million 2006
A film set in the British West Indies, predominantly starring British actors.
4. Harry Potter and the Philosopher's Stone $976.5 million 2001
A film based on a novel by a British writer, entirely starring British actors.
5. Pirates of the Caribbean: At World's End $960.6 million 2007
See 3.
6. Harry Potter and the Order of the Phoenix $938.5 million 2007
See 4.
7. The Lord of the Rings: The Two Towers $926.3 million 2002
See 2.
8. Star Wars: Episode I - The Phantom Menace $924.3 million 1999
A film set in a Galaxy Far Far away, starring mostly British actors.
9. Shrek 2 $920.7 million 2004
An animated film voiced by predominantly US actors (altough several of the main characters are voiced by British actors, they are either the bad guys or stupid).
You actually have to get down to 12 - Spiderman 3 for a proper US film.
The point I was trying to make was that world-wide the most successful films are those based on British derived material and largely starring British actors. They were, ofcourse, largely US financed and certainly some had token US stars.
However, my argument comes unstuck if you look at the US box-office...
1. Titanic $600.8 million 1997
2. Star Wars: Episode IV - A New Hope $461.0 million 1977
3. Shrek 2 $441.2 million 2004
4. ET: The Extra-Terrestrial $435.0 million 1982
5. Star Wars: Episode I - The Phantom Menace $431.1 million 1999
6. Pirates of the Caribbean: Dead Man's Chest $423.3 million 2006
7. Spider-Man $403.7 million 2002
8. Star Wars: Episode III - Revenge of the Sith $380.3 million 2005
9. The Lord of the Rings: The Return of the King $376.9 million 2003
10. Spider-Man 2 $373.6 million 2004
Rather more US led.
However, I think you need to consider that historically the US & UK have been closely tied right from Colonial times through independance, the world wars and up to today. Naturally a lot of stuff coming out of the US film industry will relate to this relationship and not always in the best light. I'm not that fussed if some mid-westerner gets the idea that the US fought and won WW2 on it's own. I'm more worried about how the rest of the world views us, and by the looks of things we're something of a hit!