Just a short bit, because I liked the question: I always related a lot to Jo March as a kid, since I was a writer too. So many people identify with Elizabeth Bennet--probably because she's just that well-written a character--but more specifically, I always identified with Elinor Dashwood (my sister is very much a Marianne); I tend to choke a lot of things down. And Jane Eyre and Sara Louise in Jacob Have I Loved appealed to me a lot for that sense of outsider-ness, of not fitting in.
(As a side note, I try to find something I can identify with, or at least understand, in every single character I write. It's a useful way to prevent cardboard villains, for example. You know, what beliefs do they hold, or habits do they have, or what do they really want, and can I identify with wanting that, even if I don't want it for myself?)