Mine aren't that bad really. They're mostly just a bit odd. I have a bit of an obsession with airplanes and air travel in general. Like, I'll look up different makes of airplanes, how many people they'll, what the seat layout is like, stuff like that. And I'll go to airline websites and compare what they're services are like (which is mostly depressing these days).
I have a few others which you might found even in NTs, but not quite to the same magnitude. Lets see... This musical called Chess, which is about the Cold War and how political the chess tournaments became during that time. It's obscure but I love it and can spend hours looking up videos on Youtube. Same goes for Wicked, except that it's less obscure.
Oh, and Communism and the Soviet Union. It fascinates me that it didn't work better than it did. There are so many places where if things had been just a little bit differently everything could have turned out so much better. As is, I often think that life in the Soviet Union, at least in the later years, wasn't quite as bad as the Americans portray it.