Some of these need to be rewatched actually.

[Excluded]
• Don't Look Now (1973) = It might have some giallo elements in it, but overall it's not one.

• Dario Argento's Mother Trilogy = The trilogy consists of Suspiria (1977), Inferno (1980) and Mother of Tears (2007). They are basically supernatural horror movies.

• Stage Fright (1987) = Even though some consider this one a giallo, I think it's simply a slasher movie. There is no murder mystery, and it doesn't really feel like a giallo.

• The Phantom of the Opera (1998) = It's a gothic horror movie, not a giallo.

• Pieces (1982) = Although it feels like a giallo to some extent, I'm not so sure whether it can be categorized as a giallo or not. It's mostly considered more of a slasher than a giallo, so it's excluded from this list for now.