Silly bonzles, there isn't a 'best', just a long list of good ones
Including:
Suspiria,
Blood on Satan's Claw,
The Wicker Man,
2001: A Space Odyssey,
Blow Up,
Berberian Sound Studio,
Valerie and Her Week of Wonders,
Bullitt,

Oh and loads more that I can't be bothered to think of right now
( tangledupinblue hairy badge with moving eyes, Mon 12 May 2014, 13:18, 2 replies, latest was 12 years ago)

There is always a best something

(Bonzodog29 is an unemployed sponge of the worst kind, Mon 12 May 2014, 13:21, Reply)

YM won best in show

( sporters I’m sincerely gratitude to you, Mon 12 May 2014, 13:22, Reply)

Sure did
Shame the "show" was anal intrusion 7
(Bonzodog29 is an unemployed sponge of the worst kind, Mon 12 May 2014, 13:28, Reply)

The main theme in Bullitt is excellent

( sporters I’m sincerely gratitude to you, Mon 12 May 2014, 13:21, Reply)

Everything in my list is excellent

( tangledupinblue hairy badge with moving eyes, Mon 12 May 2014, 13:24, Reply)

Wrong
That nick cage film shouldn't be in there
(Bonzodog29 is an unemployed sponge of the worst kind, Mon 12 May 2014, 13:29, Reply)