Mirror
Mirror is enchanting. My first watch I thought it was technically exceptional, but knew I was missing pieces of the puzzle. Then I decided to rewatch it and finally clicked.
There is something special about Mirror. Tarkovskys most famous films always have an otherworldly sense to them, be it the presence of God or sci-fi coldness. Mirror is something else. It is a deeply human work by a genius in the prime of his career.
Go watch it. I need to hug my mom.