Deep Red is one of only two 1970s movies in the Internet Archive Top 100. (The other is at #99.) It’s an Italian giallo thriller starring Macha Meril as a medium and David Hemmings as a pianist who investigates a series of murders performed by a mysterious figure wearing black leather gloves.
The Internet Archive version is the US release, which cut 22 minutes including the most graphic violence. Deep Red is still not my favorite kind of movie, but its strong critical reception, especially from tens of thousands of IMDb voters, boosted it to this list.