Stephanie Cutter
V. Stiviano
Octomom
Casey Anthony
First: Oops.
Yes, females. Somehow I missed that.
But frankly it doesn’t dramatically change the underlying point. Someone upthread mentioned Karla Homolka and Charlene Gallego – how in the world does Sarah Palin, Nancy Grace, Lindsay Lohan, or Michelle Bachman come anywhere near the depravity of Karla Homolka, Aileen Wuornos, Delphine LaLaurie, Charlene Gallego, Myra Hindley, Ilse Koch, or Irma Grese?
Jan Brewer? Nancy Pelosi? A woman holds contrary political positions and that leapfrogs her over fucking torturers and serial killers for “least favorite?”
Heather Mills McCartney
Elizabeth Bathory holds the title for me. It doesn’t get much worse than bathing in your victims’ blood.
But the poll is about “least favorite”, not “most evil.”
In that case: My ex-girlfriend.
I think that she has caused more harm than most of the other women in this thread combined.
Aileen Wuornos, Delphine LaLaurie, Myra Hindley, Ilse Koch, Irma Grese, and Elizabeth Bathory are all dead.
Anyway, in my mind, Jenny McCarthy and Lea Thompson are responsible for the deaths of unvaccinated children whose parents listened to their ignorant rantings. I’m not sure that Karla Homolka had more victims than people who brought back measles and pertussis as their weapons.
Not to worry, Good People! If this poll comes to be, and I think once we get 50 candidates I’ll start one, you can decide for yourself who your “least favorite” is and what that means to you.
I’d just like to hope that SDMB voters can arrive at as close to a consensus on this topic as we did on picking Christina Hendricks as “most voluptuous” a while back.
There are some noteworthy names not yet on the list, but I don’t want to provide clues for them. 
Also dead.
Indira Gandhi did some pretty awful things (though not on the order or murdering lots of people, AFAIK.)
ETA: Just noticed they have to be alive.
Mother Teresa is my least favorite female human, but she’s dead. Did anyone else read the OP? we’re supposed to be nominating living people.
Queen Mary I (England) also known as Bloody Mary. Most Evil historically
Least Favorite in today’s world. Righties gonna say Hilary. Lefties gonna say Ann Coulter, or someone like her.
Was going to say Mother Teresa. She has this image of helping the poor, but what she actually did was help them BE poor. She believed that being poor was a pure gift from god. She spent her entire life opposing the empowerment of women, while endorsing the very things that kept them down, especially reproductive rights. She followed the recipe for success in all religions, which is to keep the flock poor, uneducated, and docile for generation after generation, to ensure the church can keep it’s mystery and power. When she died, her works in Calcutta were in underfunded and largely ineffective, just as was when she started.
Oh, gotta be alive? Well crap. Guess I’ll go back to Coulter.
Gotta be Hillary Clinton. Closely followed by Michelle “My Belle” Obama and Nancy Pelosi.
Okay, I get it. Hillary and Nancy, sure, I get it. Righties hate those two just like Lefties hate Sarah. Got it.
Why Michelle? What gets her on this list? Not that you’re required to justify, just asking.
Yoko Ono and Hanoi Jane Fonda.
I don’t forgive easily.
That too? Man, this poll is getting restrictive.
Well, good news for my ex-girlfriend, since it means that I can’t kill her for a while yet.
(Edit: I wouldn’t really do that. She’s actually a lovely person.)
(Charlene G is new to me. I’ll go read up.)
I am staunchly against the death penalty. The only case about which I’ve ever thought “Oh, now the death penalty makes sense to me” is Karla Homolka’s. That she’s out and about and using oxygen that would be better used by anyone else fills me with ire.
My absolute least favorite female is my late husband’s first wife. Now that bitch is evil.
My least favorite that you’re more likely to have heard of is probably Rhonda Byrne (the chick who wrote The Secret.
To be fair, while Karla Homolka was a terrible sister, for the right guy, she was an amazing girlfriend.
Too soon?
Barbara Bush (the old woman, not her granddaughter).