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. :-)

Cassandra Wilson is excellent! Jacqui Naylor is pretty good. Karrin Allyson is good; In Blue is mavorite album of hers. I have an album by Paula West that I enjoy called Come What May. People also Like Stacy Kent. Plus there is the older generation like June Chrusty, Rosemary Clooney, Shirley Horn, Billie Holiday, Ella Fitzgerald, Sarah Vaughn...
She'd be horrified to be mentioned in the same breath as the three above, but Patricia Barber is a true great, in my view.
check out Joni Mitchells BOTH SIDES NOW. I initially hated this recording, feeling that her vocals on MINGUS were much more her own. Still, her phrasing on these songs still have signature joni mitchell characteristics, and the recording as a whole is well put together. Going 180 degrees elsewhere you might want to check later recordings by Etta James. Cassandra Wilson is a must.
Norah Jones is anything but a jazz singer. Everytime I think I might want something by her, I listen and say "no thanks I've heard it before by better". I'm right there with the older generation singers listed by Budrew and will throw in with Joni and Rickie Lee too!

Over the last few years I've built my entire system around the nice discovery you've made. Nothing like a lovely female voice in a dark room.

Also give Jacintha and Diane Reeves a try. And, if you're open to some beautiful female voices of Bossa Nova, look into Ana Caram and Paula Morelenbaum.

I've slways loved Sarah Vaughn, Ella Fitzgerald, and Shirley Horn. I'll have to give Cassandra Wilson, Etta James and Joni Mitchell another spin. It's been awhile.

Have fun!
IMO, I don't think that most of the female jazz singers on today's scene hold a candle to the "greats" of the 1940's through 1970's, probably because the fine vocalists of that era learned their craft singing to live audiences, backed by stellar musicians in the big bands of the time. Among the "greats" I'd start with Sarah Vaughn (arguably the best woman jazz singer ever), plus Billie Holiday, Ella Fitzgerald, Dinah Washington, Ernestine Anderson, Sheila Jordan, Betty Carter, Nina Simone, Carmen McRae, Abbey Lincoln, and Shirley Horn. The list of excellent women jazz singers in the past 15 years would include: Diane Schuur, DeeDee Bridgewater, and Cassandra Wilson, with the following "new" names also deserving of mention: Kate McGarry, Nneena Freelon, Lorraine Feather, and Luciana Souza (chosen by recent Downbeat poll as top upcoming female singer).

If you really get interested in the history of female jazz singers, you should also go back in time and listen to the following blues/jazz artists of the 1920's and 30's who shaped the vocal art: Bessie Smith, Gertrude "Ma" Rainey, Bertha "Chippie" Hill, Ida Cox, Victoria Spivey, Sippie Wallace, Alberta Hunter, and Adelaide Hall.
Not strickly jazz, but a good listen: Rickie Lee Jones, Holly Cole & Karrin Allyson. Kind of quirky but another I would recommend is Patricia Barber.
Thanks for the multitude of suggestions. I'll certainly have to check out many of them. Thankfully, you can take test listens of various artists at so many places (both online and B&M) now that I'll be able to see what each sounds like before buying.
Another big vote for Cassandra Wilson!!! Judging by the others you mentioned, you might also want to check out Eden Atwood and Carole Welsman. you might also like Robbie Williams "Swing while you're winning" CD.
My favourite female jazz vocal is Flora Purim.
For male I'd go with Donald Fegan(jazz-rock vocal)
Eva Cassidy, who tragically died so young. Acclaimed in Europe, and nearly unknown here.

Eva Cassidy is just amazing - try all of her CD's. Her rendition of "Over the Rainbow" on her CD Songbird will bring tears to you eyes.
Grab Steve Tyrell's CD titled "Standard Time". Track # 5 has a great duet of Steve Tryell with Jane Monheit, "Baby Its Cold Outside" that will knock you out. The rest of the Tyrell CD is a treat (every song).
Try Etta James CD titled "Love Songs". Tracks 1,2 & 8 are great songs from an enormously talented singer.
Glad to see someone mention Tierney Sutton. You have some great suggestions - BUT to anyone who hasn't heard this following woman - you owe it to yourself to at least give her a listen - Jackie Allen!
PS - for male jazz singers, try

Philip Manuel

Jamie Cullum (really)

Kevin Mahogany

Steve Tyrell (already mentioned)

Michael Bubble

Johnny Hartman

Kurt Elling

Just to name a few

I would second Jamie Cullum and add Matt Dusk,Peter Cincotti. Try to give Stacey Kent a listen.