Otaku in japanese is used primarily to describe someone who is obsessed with something to the point of un-healthiness. They lose their grip on reality so to speak. 'Gun-Otaku,' one who is obsessed with guns. 'porn-otaku,' one obsessed with porn. so on and so forth. The american meaning, maybe its used else where to...I dunno. any way, otaku over here is someone who likes anime a wwhhoollee lot, though they normally lead a normal life (unlike jap. otaku). Not really a bad term, though many see it as such.
No example. Its self explanitory.
'Otaku' is someone who is obsessed with something to the point of un-healthiness by japanese definition, but by american definition, it means 'someone who likes japanese animation a LOT.' So, by japanese def, an animation otaku is someone who loves animated pictures to the point of obsession and only liking animation. By american def, one who likes anuimation, mostly jpanese in nature.
The 'animation otaku' woke up, watched cartoons all day (american or jap or whatever) then passed out after his/her sugar intake reached dangerous levels from eating candy bars, cereal, and sugar packets all day. That also means their fat and smelly. Whee!
Manga is the japanese word which, more or less, refers to any illustrated story, but now is directed more or less towards comics only.
The real version of manga can be used to refer to moving pictures as well.
Battle Angel Allita (Gunm) is a great manga series.