Here I have to admit, that John Williams is my absolute top favourite. From all other composers in my top 10 I like aproximately 30% of their work. And their ranking results from how much I like their great 30%.
And of course the list is just a momentary picture.
And main criterion for me is how much I like their music. How well it works in which movie is secondary for me.
1. John Williams
2. Miklós Rózsa
3. Jerry Goldsmith
4. Elmer Bernstein
5. Philippe Rombi
6. Joe Hisaishi
7. Philippe Sarde
8. Bernhard Hermann
9. James Newton Howard
10. Dario Marianelli
Honorable mentions:
Danny Elfman
Franz Waxman
James Horner
Alan Silvestri
Howard Shore
Christopher Young
Patrick Doyle
John Barry
Ennio Morricone