There are so many great SF/F women authors with "B" names that I couldn't limit myself to one. One could say they are quite bountiful, even...
Gael Baudino--I included her because Gossamer Axe introduced me to lesbian characters and made me sympathize with them. (Prior to that I didn't know much about them--yes, I was sheltered.) Fiction is a wonderful way to open the mind, especially if it's science fiction.
Author Page on Amazon
Marion Zimmer Bradley--Despite the deplorable accusations of child sex abuse that came out last year, MZB is too well-known to be left off this list. I was a big fan of her Sword and Sorceress series for a while and thought about submitting a short story to this anthology, but I didn't get anything to the point where I felt it was worth submitting. The series is still going strong, so maybe I should come up with a story for it.
Link to books on Amazon
Lois Bujold--A relatively recent discovery for me. I was awed by her Chalion series--and a bit embarrassed that my Season Avatars series (which I first drafted long before I read Bujold) features both season-based deities and a country named Challen. We take the basic ideas in vastly different directions, IMO. I'm not very far along in the Vorkosigan Saga; I recently read Cordelia's Honor. I plan to get the next book in the series when I return to the library.
Link to books on Amazon
Lindsay Buroker--An indie fantasy author who's become an automatic buy for me. Her books feature witty dialogue and plenty of action. She also offers good marketing/business advice on her blog.
Author page on Amazon
Honorable Mentions: Terri Bruce, sister member of Broad Universe and the founder of the Blog Ring of Power. She has a series about a ghost's journey through the afterlife.
I've read some of Elizabeth Bear's work and respect her writing skill. Unfortunately, I can't think of the titles I've read at the moment, but I do have a few samples of hers in my immense TBR list.
Special Honorable Mention to all the members of Broad Universe, which is dedicated to promoting women writers of science fiction, fantasy, and horror. It was founded at WisCon fifteen years ago, and I'm proud to say I'm been a member since the beginning. We support each other online and at conventions. I'll be featuring some of these women individually during the rest of this blogathon. You can find the current full roster here.
Got any comments about these authors, or do you have more to add to the list? (I'm saving Octavia Butler for a critical position in the alphabet, so I didn't forget her.) Feel free to discuss them below.