Someone on 2chan has ranked various types of otaku (obessive fans) on two axes: how crazy they are, and how much trouble they cause. Here's the original Japanese chart:

And here is the English version I made:

Please note that spacing in the above graph is only approximate. For accuracy, refer back to the original.

Here is a smattering of translated comments from the thread: 

No smart phones? You should swap that in for gaming hardware.

Anime and figurine otaku don't cause any trouble! At worst, they only cause traffic issues during Comiket. 

Manga otaku and anime otaku are about the same probably. Even though they both have high levels of craziness, why is manga nonchalantly placed at a lower craziness level?!?

Yeah I guess a stamp collector is pretty representative of a harmless otaku.

Oh, adult games are right about in the middle! So I can put my mind at ease and play tentacle games.

What's wrong with liking voice actresses? What part of that is bad?

Voice actress otaku are good people! Good!

Too many crazy people are commenting.

Vocaloid is too low. That group includes the Nico posters so they are the most annoying.

Even though camera otaku cause the most trouble by a long shot...

via Yaraon!