In my first list I was avoiding films labeled as horrors, but this time I will put such films only because I consider that they have a deeper meaning. Some of this films only have some dark scenes but are not overall dark. And also I consider existential horror to be very dark.
waiting for godot 2001
Ikiru (to live) 1952
eraserhead 1977, the grandmother 1970, the elephant man 1980
Mary and Max 2009 and anything else from Adam Elliot (clay-animated films!)…