V for Vendetta has enough material for a 26-episode series. All they need to do is work out a proper ending.
The book
Ender's Game could probably be adapted into an anime, if the characters are made a bit older.(6 year-olds killings stuff seems a little too weird, even for anime)
There was also a Chinese live-action movie that looked kinda like Final Fantasy VII.(sorry, can't remember the name) It just looked too awesome to NOT be adapted into an anime.
And of course,
Shaolin Soccer is a hilarious movie that deserves an anime adaption.(though I'm not sure if it can transfer well into an anime format...) I'd like to see animated versions of the characters pulling off Jutsus.
