Let's see.. I've nuked a town of innocents, run-down civilians by the truckload, split up families by denying entry to the mother and thus dooming her to death in her war-torn country, fired a mortar of [REDACTED] at [REDACTED] and starved entire cities of food. Possibly taking the evil biscuit is Spore and using terraforming tools to mess with a planet's atmosphere, turning a well-populated, lush planet into an airless, frozen, barren, dead rock.
What's the nicest thing you've done in a video game?