We'll hold our hands up and accept that we're now getting onto objects which you're less likely to have hanging around, but that doesn't mean to say there isn't someone who is or was an avid comic book collector somewhere in your family tree. Who do you know who has a collection of comic books piled up from floor to ceiling in a room, and is always being told to get rid of them? Could they have a copy of the first-ever Action Comics book in there somewhere? If so, tell them to sit down before you explain what it's worth.
Action Comics #1 is especially famous for one good reason - it's the first ever adventure of Superman, who would go on to become the most famous superhero of them all. Even badly damaged copies of this comic are worth more than $100,000 because of their rarity, but the last time a pristine copy went for auction it sold for in excess of $2m. The actor Nicolas Cage famously owns a copy.