I voted for Suspiria. I saw this film for the first time about two weeks ago and just LOVED it. Easily one of my favorite horror films. The story is basically a fairy tale, and the vibe the film gives off is so surreal. The cinematography is beautiful. I love the way they played with the primary colors--simply breathtaking! And I can't even begin to describe how much I love the score! I bought the limited edition 3-disc set, which is WELL worth its price. It includes the Goblin score and a documentary. The documentary adds so much to this film.

This is the only Argento film I've seen. I definitely need to check out more of his films. Given the results of this poll, I think I'll check out Phenomena and Tenebre next.