• Gothic 2, and by extension, Chronicles of Myrtana
• The Binding of Isaac: Rebirth
• Both are equally as monumental, so it’s shared between Obra Dinn, and Outer Wilds

That being said, i’ve excluded any mmos out of this list, purely because sometimes i struggle to call them my favorite games, despite having playing several thousand hours of each. Some of them have been unbelievably impactful at certain times in my life, but i’m afraid the embers are getting cold now