If you're going to do a lesson about a videogame in school, then you have to know what you're trying to use this game to teach. If we're teaching proper coding, then I have no idea, so game with good coding. If we're taking a look at game design, then one can safely assume people in this class have played a Mario game or at least a similar platformer, in which case you be best taking a look at games taht are hard to classify in terms of genre, like Killer 7. Someone mentioned Bioshock for a politics class, but I don't think it would get across Rand's philosophies as well as say, The Fountainhead, or Atlas Shrugged.
Games are a useful method for conveying a learning experience, but we have to know what's trying to be conveyed first. I can get someone to read Watchmen as their very first comic or watch Citizen Kane as their first movie, but they're not exactly going to appreciate the nuances of either unless they have some background knowledge on the medium.