you start collecting the mangas to the anime (friend of mine has about 530+ mangas with the anime dvd's) and start making your own collection

dream about the anime

cry and feel empty when you see the last episode

look for anime on youtube/veoh/etc and spend hours watching it on the computer

and ask your friend if she/he's seen any of the mangas or anime that your trying to collect in any of the book stores she/he's been in

you know you're otaku when
 

you give your friends nicknames from anime/manga (hachi, nana, reira, etc.)
you start a club at school just to talk anime/manga/music
:pompoms:

Go into withdrawl after finishing an anime because there's nothing left of it to watch

You acually shoplifted Manga. (it's true)

Otaku extreme
 

1) when you only watch Japanese anime on tv or anything that says anime.
2) when you get mad at people who pronounce Naruto wrong
3) when you have all the details right and had remember every war off Gundam seed, including the bad guys and what is a coordinator.
4)when you cry when a character dies

But it's all good.

when you correct your parents everytime they call anime cartoons

when you have to correct misinformation on what anime is to your family

You think everyday about how cool it would be if life was anime.
You get mad when your friend says the anime you're making should have an english theme.
You ARE unstoppable with a sword:)

omg
 

i've shoplifted manga too. *nervous laughter* which one did you shoplift?

You Get Hard Over A Anime Babe/guy,...

Xd

When you dream about anime on a regular basis XD

you feel pissed off when someone doesn't like anime and want to kick their ass for saying bad stuff about an anime you like

you LOL at someone who mis-pronounces the word anime and make them feel worthless i.e. when they dont pronounce it "ani-may" but instead pronounce it literally .