6. Citizen Sleeper: Flux/Refuge/Purge DLC The writing in Citizen Sleeper is top-notch, and the three DLC episodes released this year didn't disappoint. I'm looking forward to the sequel, and I hope to go back and finish In Other Waters, the developer's previous game.
4. Myst This is the game that originally inspired me to get into software development, if I remember right, so I guess it has a lot to answer for. But despite having given it a few gos over the years, I never got more than one or two ages in. I finally finished it this year and really enjoyed the experience.
3. Return of the Obra Dinn The game that I played immediately after Myst, and a good companion game. It requires fairly undivided attention over a few play-throughs, but it's well worth it. I had given it a try a couple years ago but didn't have enough time to dedicate to it, and I'm glad I went back.