My favorite boardgame
...is Deep Sea Adventure, by Oink Games. It's an extremely simple, extremely short game, where players choose how much of a shared resource to risk in order to gain individual rewards.
It's not quite "prisoner's dilemma: the game," but it does have enough "coopertition" for it to play significantly differently with different groups of people. It's easy enough for my younger relatives to understand, and like all of Oink's best games, it's only a little bigger than a deck of cards. It's a great game, but it's mostly my favorite due to hitting a median level of delight on all the metrics most important to me. There's other games I've loved more in different moments, but this is the one I bring on every vacation, basically.
One of the other reasons I like it so much is that I have a number of friends and family members who REALLY enjoy it, but refuse to buy their own copy. So I get to be the one who shows up with The Fun Short Game Everyone Likes But Keeps Forgetting To Buy, and I can save the day with it. I've owned my copy for a decade and have photos of my friends playing it back to 2016.
Oink is absolutely my favorite board game publisher, and I own quite a lot of their itty-bitty little games. They've published several updates or expansions to Deep Sea Adventure which I haven't yet played myself, though. I have played quite a lot of A Fake Artist Goes to New York, however - it's probably my second favorite of their games.
Anyway... this is not a particularly rare or unusual game, and I'm not cool for liking it so much, and I've got other games that I like better for other moments. But this is basically my suitcase game, my family-is-visiting game, and I had a chance to play it again recently. It's still great!!