Okay, this depends partially on if you're talking about the comic or movie. In the movie, V is a little quirky. In the comic, he is completely bat-shit insane. He actually acts out a huge dialouge between himself and Lady Justice, while standing alone on a roof-top. And he speaks for both parts, himself and Justice. V is one of the craziest heroes I know, and that's counting Ted Nugent. MY HERO!

For me he's very much insane. Come on, if we're talking about a man who devoted himself for his mission so much he even thinks about himself as an idea... And a man who has such past? He can't be sane, not a chance.