What video game would you say has taught you the most about something that you’ve been able to use in the real world? This can be a simulator, or it can be any random game whose story or mechanics left you a little bit better off (Runescape taught me how to type).
In early Wrath of the Lich King I took over the entire jewelcrafting market on my server. It taught me a lot about real life marketplaces and economics.