One that's particularly interesting to me is how I managed to learn a not insignificant amount about 20th-century warship design from playing the Rule the Waves games.
Like...this is a series very obviously designed for hardcore wargaming nerds who already know stuff like what the hell the difference between a protected cruiser and a light cruiser is or the benefits of putting all of a ship's guns at the front, and it's obvious enough if you look at the extremely old-fashioned interface and graphics consisting entirely of vector drawings and stock photos. But anything that's meant for armchair experts on a subject is by necessity probably detailed enough to turn someone into an armchair expert on that subject, and that's exactly what happened to me in this case