It’s a card game rather than a board game (but still within the tabletop sphere so I think it still fits): I absolutely love Sentinels of the Multiverse. It’s by the same people who made Spirit Island, which I believe is more well-known. It’s a cooperative game where you play as superheroes working together to take down a villain. Aside from the game itself being a lot of fun, there’s a bunch of hidden story and lore within the card art, and the creators even have a podcast where they create stories and characters within the game’s world.