Funny, the DVD of that one just came in the mail from Netflix.
Sweet! The plot isn't particularly good or anything and the logic is flawed, and it's not nearly as good as SUSPIRIA imho, but the kills are so nasty it's awesome!
Watched it and enjoyed it. Some pretty cinematography, and I dug the music too (usual for Argento, he's got good taste there). That crane shot of the apartment was probably the visual highlight. And yeah, the kills aren't extremely gory (compared to the more creative ones in a film like Friday the 13th part 4 or something), but they have a certain brutality and nastiness to them that reminds me of a punch to the gut.
Chopping Mall
Good suggestion - I've seen it, but I'm looking for suggestions for a party, and I think it'd be great for that.
Invisible Maniac (especially recommended if you liked the Slumber Party Massacre series)
That movie is kind of hilarious. Especially the ending.