Genshiken is this hilarious manga about an Otaku club, and all its sterotypical members. there's the guy who always wants to test how hardcore you are, and the guy who only plays pornographic RPGs, and the guy who seems normal and popular and even has a pretty girlfriend, but is secretly the biggest geek of them all. if you have ever been in such a club, or dated someone who was (or both), it's the funniest goddamned thing in the world.
anyway, upon discovering this, i had an outburst at the desk amidst the silently studying 14-year-olds (that sounded a lot like the noise you make when you open a balloon and tweak the opening just right), and this time could in no way pretend that i was not doing something outrageously geeky.
but then again, earlier today i took a poll amidst my kids about fanfiction, because of an article in my WIRED which said 5% of their readers did it, and about 2/3s of my kids admitted to doing it. *cackles in sekrit glee*