I'll start, though my list may be revised as I think.
Anyway, here goes so far in no real order:
Nosferatu - Murnau,1922 - silent
M - Lang, 1931
Black Sabbath - Mario Bava, 1964
Les Diaboliques - Clouzot, 1955
Audition - Miike, 2000
The Cabinet of Dr. Caligari - Wiene, 1919 - silent
Eyes Without a Face - Franju, 1960
Faust - Murnau, 1926 - silent
Spoorloos- Shuizer, 1988
And one I have not seen, but really want to (though there are no DVD/VHS ways to see it)
The Phantom Chariot - Sjostrom, 1921 - silent - Sweden (that one would satisfy my craving to see scary chariot rides, I think)
What are your top ten?