Diana Krall, Norah Jones, Jane Monheit....?

Well, within the last 6 months I've found that I have a love for female Jazz singers. It started with Diana Krall and then Norah Jones and as of the last couple of weeks, Jane Monheit. Any recommendations on other great female jazz singers? How about male jazz artists?

It's always fun to explore a new genre and I love what I hear so far. :-)

Jeff