Oh, and China Miéville has some strong female characters: Bellis from The Scar, Marge in Kraken, Avice in Embassytown.
never mind.
Ilona Andrews - a husband and wife team - have both the Kate Daniels books - where Kate is an extremely strong character, as well a the 4 book Edge which are a little more romancey than science fiction but still have nice strong female leads.
P. M. Griffin did a series called Star Commandos. She had a multi-year hiatus between the first 9 books, which are good, and the last 3 books which are excellent. Commando-Colonel Connor is a very strong woman.
There are some good strong female characters in Jacqueline Lichtenberg and Jean Lorrah’s Sime Gen series. Ambrov Keon and Mahogany Trinrose both have strong female protagonists. You pretty much need to read some other books in the series that don’t have as many strong women to make sense of these, though, as the series is highly interconnected.
S.M. Stirling’s Nantucket trilogy has Marian Alston, a Coast Guard captain. Without her the people of Nantucket would most likely have gone down the tubes, or at least not done as well as they did.
She’s a go to character for three reasons, as she herself knew.
She’s female, in a traditionally male job.
She’s female, and black.
she’s female, black, and lesbian.
Seanan McGuire’s October Daye series (I assume her other work, but I’ve not read them(well, I read the Newsflesh series that she wrote as Mira Grant).
C.E. Murphy’s Walker Papers series (again, I’ve read that series but none other).
Anything by Octavia Butler.
On the YA side, all of Tamora Pierce’s work.
The Wolf series by Jane Lindskold. In addition to having a strong female protagonist (who gets to have flaws that are an actual hindrance), the series also boots a lot of the tropes I dislike in fantasy about animal characters and feral children. Links go to sample chapter on author’s website.
- Through Wolf’s Eyes
- Wolf’s Head, Wolf’s Heart
- The Dragon of Despair
- Wolf Captured
- Wolf Hunting
- Wolf’s Blood
I think Peter F Hamilton writes the BEST female characters, especially in his Confederation novels. In addition to hating the “traditional” female stereotype I also hate the “strong woman who overcomes odds to become a starship captain” stereotype…boring boring boring.
Hamilton’s characters tend to be ordinary women thrust into extraordinary circumstances. Take. Araminta, the main character in the Void Trilogy. She’s a young divorced woman trying to start a real estate development business…and rather scornful of the religious cult that is inundating her planet…when she accidently becomes the star player in the cult’s quest.
I often say his great female characters are what makes him my favorite author.
The Handmaid’s Tale by Margaret Atwood.
Susan Calvin was the central figure of Asimov’s I Robot stories.
Sister Light, Sister Dark and White Jenna by Jane Yolen
The Female Man and most everything else by Joanna Russ.
James Morrow’s Only Begotten Daughter
Staroamer’s Fate and its sequel Syron’s Fate (both soon to be republished by Fantastic Books).
James SA Corey’s two books–Leviathan Wakes and Caliban’s War–have some good female characters. The latter especially has some great scenes between two women in traditional male roles: the female marine and the female political bureaucrat. They’re great fun.
Philip Reeve has some real winners.
Hester Shaw from the Mortal Engines books is brutal and amoral, and she’s the protagonist; it’s the male love interest, Tom Natsworthy who is the sunshiney, optimistic, has-to-be-rescued half of the couple. And Fever Crumb from the prequels is pretty tough too.
I’d also mention Gwyna from Here Lies Arthur, the young girl telling the story - she and “Myrddin” are playing a dangerous game of politics in Arthurian Britain.
And for laughs there’s the steampunk Larklight trilogy; one of the main characters, Myrtle, tries to be a prim and girly Victorian lady but to her dismay persists in being competent in dangerous situations.
Brandon Sanderson’s awesome “Mistborn” trilogy has a female main (Vin) who is strong in every sense of the word 
Interestingly, he has a blog that diaries the writing process and keeps earlier drafts of work for public view, and this character had originally been male - making Vin a young woman somehow is just the right touch.
For a while you could download a novella of his for free called “The Emperor’s Soul”’ an excellent quick read that also has a strong female central POV.
Don’t forget her Vicki Nelson from the Blood books
I have a soft spot for Warrior’s Wings series
Independent author and military SF but has a strong female lead that is still female, not a male character with a female name.
This is like a blast from the past…strong male character who outsmarts and outfights against vast odds - is always right - never makes a mistake and has several ‘strong’ female characters who seem to exist soley to throw themselves at the lead male character.
Very cliche, very juvenile…but WELL DONE IMO 
:).
I concur with
-C. J Cherryh (be warned that she writes broken characters)
-Lois McMaster Bujold. I didn’t get into the Sharing Knife but her Chalion and Barrayar series have realistic women
-Terry Pratchett
-Tanya Huff - Confederation.
-Ilona Andrews - Kate Daniels. Her other series also has strong women but I didn’t like it as much.
-The Jane Lindskold referenced above but it’s more a feral, female character.
-Garth Nix. Sabriel is a beautiful book.
I disagree with Susan Calvin. She’s nominally female but (IMO) is a cardboard cutout. I’ve read a couple of Heinlein and his women, again IMO, tend to be male fantasies of women.
I’m adding several authors to my list based on this thread.
What I came in to mention. Also Deeba from Un Lun Dun and Natasha from King Rat.
Also Teela Brown from Ringworld, and Podkayne of Mars of course.
I disagree completely! Yeah, Lirael starts out kind of whiny and helpless, but that’s the whole point of her coming of age story - she comes into her inheritance and accepts her role. I think the adult Lirael of the third book is a great role model.
It’s worth noting that Jack Vance, toward the end of his career, finally did manage to write a book with a strong, believable, likeable, competent female protagonist. For MOST of his career, his female characters were space princesses and other nonentities. But in Ecce and Old Earth, second book in The Cadwal Chronicles Trilogy, the character Wayness Tamm marks a breakthrough success in Vance’s writing.