To Boldly Go...
I would (and, in fact, am) recommend Space Exploration: Serpens Sector to anyone seeking to fill a few random half-hours with seeking out new life, and new civilizations in a randomly generated cluster of stars. It's a lot of fun, and there's interesting little interactions based on your crew and previous actions in all sorts of places, so even if you think you've found all the quests, there's still lots of little things to make repeated playthroughs worthwhile. And not every tactic will work the same each time, so diplomacy isn't just a matter of memorizing responses.