And some non-GOG gems, to continue this trend:
Elite: Dangeous - best space-sim out there, no other comes close. Also one of the few live-service games with a great community around it.
Anno 2205 - Seem by many as the black sheep in the anno series, it's still a great game with a fantastic future vibe.
Craft the world ( hey, it's also on gog ) - dwarf fortress like game
Civilization: Beyond Earth - Firaxis' attempt at a contemporary Alpha Centauri, based on the Civ 5 engine. Great game in itself, with some great ideas. Also gets a lot of hate for some reason.
Planetbase ( also on gog ) - Great space-colony builder
Yeah, I was rounding things a bit. Great year for gaming