I like
Joan. I think it's very nice and "sturdy" sounding. it reminds me of
Joan of Arc. I don't like
Joanne.
Joanna is alright. I prefer
Johanna though (though It reminds me of
Sweeney Todd).
Similar:
Jane,
Jehanne, Jehanna,
Johana,
Johanne,
Joana,
Joanie?