Suspiria (Dario Argento, 1977)
The most famous of Dario Argento's horrors is as much about a Satan-possessed German dance academy as it is about his pungent, psychedelic colour schemes and soundtrack. Charges of all-style-and-no-substance would be missing the point.
The cast includes Joan Bennett in regal mode, a perpetually sneering Alida Valli, as well as American import Jessica Harper in the lead, who is amazingly wooden even within the campy slasher context. You want her dead early on, especially since you can never get enough of the ludicrous, wonderfully grotesque killings.