I don't really have a favorite film for San Francisco, since I like so many different movies for different reasons; but for among the films that best represent San Francisco, I recommend the
Dirty Harry series movies for starters.
For reference of movie filming locations set in US cities, look here:
source:
https://en.wikipedia.org/wiki/Catego...States_by_city
Current Top 21 Ranking of Number of Films Set in US Cities by City:
1. New York City (11 C, 1,719 P)
2. Los Angeles, California (2 C, 966 P)
3. San Francisco, California (2 C, 363 P)
4. Chicago, Illinois (2 C, 286 P)
5. Washington, D.C. (1 C, 238 P)
6. New Orleans, Louisiana (1 C, 128 P)
7. Miami, Florida (116 P)
8. Boston, Massachusetts (1 C, 92 P - TIE)
8. Philadelphia, Pennsylvania (2 C, 91 P - TIE)
9. Seattle, Washington (1 C, 90 P)
10. Pittsburgh, Pennsylvania (87 P)
11. Houston, Texas (67 P)
12. Detroit, Michigan (54 P)
13. Baltimore, Maryland (53 P)
14. Atlanta, Georgia (50 P)
15. Cleveland, Ohio (39 P)
16. San Diego, California (31 P)
17. St. Louis, Missouri (28 P)
18. Dallas, Texas (1 C, 22 P)
19. Phoenix, Arizona (21 P)
20. Portland, Oregon (20 P)
21. Memphis, Tennessee (17 P)