How about almost every single King's Quest, in original packaging. Those must actually be worth quite a bit at this point, right? Oh, also Maniac Mansion (with those damn huge disks), Day of the Tentacle, Loom, Legend of Kyrandia 1-3, Freddy Pharkas, Laura Bow: The Colonel's Bequest, Monkey Island 1-3 and probably some more old school adventures I can't remember right now. Good times.