I and everybody who browses the Off-topic Discussion board will admit that "Who would you be" is a common question. Yet you know me, I like to make you stop and think about your answer.
Which anime character would you be? What is it about our choice that makes you want to be them. For sure your choice has a troubled past or glaring fault, could you live with that? Could you also live with their fate or destiny?
I know I've said Isara Gunther in the past. However after watching GITS: SAC, I would have to switch my answer to Motoko Kusanagi.
What sold me on Motoko was her calm yet assertive nature. She virtually never seems to lose control of herself or the situation she's in. She seems to also have a very strong intellect, a quality that I see is important in any person. She's able to make decisions on the fly, all of which seem to be the right one. Another thing that I find interesting is that she is one of several anime characters I have seen that has had a very troubled past (of which we never seem to learn), yet she never allows it get to her. The final thing that sold me was that Motoko's mind isn't restrained by physical means, and that she never truly seems to die.
The one problem I do have with her is that practically every part of her is prosthetic, including her eyes and brain. This means that there always some way to disrupt the functions of her eyes or mind, although I have only seen this happen a few times.