Outer Wilds, almost no contest. It even knocked Night in the Woods out of the top spot for me after like... I dunno a solid five years?
Beautiful visually, somehow really compelling with little to no prompting the player or solid objectives, and some of the best twists and turns in a plot I've felt in a long time. Even just the starting area and music there evokes this sense of nostalgia for a place I've never been. I love it so much.
