Real Estate Agent

Every town NPC housed at once. That's the full roster: the shopkeepers as their conditions unlock (money for the Merchant, a gun for the Arms Dealer, beaten bosses and events for the rest), the rescue NPCs found bound underground (Goblin Tinkerer, Mechanic, Wizard, Tavernkeep, Stylist, Angler), Truffle in his mushroom biome (It Can Talk?!), and the hardmode arrivals through to the post-Golem stragglers like the Princess - who requires everyone else first, so she's effectively the trigger. Build a proper street of housing early and this resolves itself by the endgame; the happiness system (Leading Landlord) rewards spreading them across biomes in pairs they like.