Cats. Portal. Portal 2. Harry Potter. Doctor Who. Sherlock. Cabin Pressure. Supernatural. Good Omens. Amnesia: The Dark Descent. Assassin's Creed. Les Miserables. Tea. Creepypastas. Gaming. Random derping.
Here’s an interesting fact: they’re not filled with real air. It’s too expensive to pump into so many of them. We just take carbon dioxide out of a turret, freshen it up a little, and pump it back in. I thought that was interesting.