Leading Landlord

Get one NPC to maximum happiness and have a chat. Happiness comes from biome preference, favourite neighbours, and low crowding - the two-per-neighbourhood rule. The stock easy win: the Ocean with the Angler and Pirate, or the Snow with the Goblin Tinkerer and Mechanic (a couple who like each other and their biome). Park the pair alone in their preferred biome, talk to them, and when their prices bottom out and the dialogue glows, it pops - they'll also sell you their biome's pylon, which is the real reward.