If you only have time for one computer roleplaying game, then make it Divinity: Original Sin 2. Also a standout: the voice acting of J.K. whose passion for her work goes to inhuman extremes. It’s also darkly relevant these days, centered as it is on a struggle with a malevolent A.I.
It’s both memorable and challenging, and those challenges are designed in such a way that you feel triumphant when you finish. It’s a puzzler at heart, but it injects those puzzles-which involve the best placement of the titular portals, which you create with a gun-into a masterful concoction of science fiction, memorable characters, and even a catchy song.