Rachel Morgan is the main character in the Hollows series of books by Kim Harrison.
She is a witch, turned day-walking demon in a world where most of the human population was killed by a genetically engineered tomato. Since then ("The Turn") the vampires, witches, weres, elves and other supernatural types came out of hiding. Witches look human but are a different species. They marry and have sex, but can't produce offspring. Witches are though more related to demons.
Rachel is an independent "runner". She is something like a bounty hunter/detective/occult problem solver. She uses magic, but since magic has limits, complications and prep time she also uses a paintball gun where the paintballs are filled with sleep potions.
There are currently 12 books in the series with the 13th and last one, The Witch With No Name, out later this year. I have not caught up yet to book 12, The Undead Pool (so don't spoil me!), but I hear it is good.
I will be honest I did not like Rachel at first. I thought she was whinny, immature and didn't earn my interest. Fortunately other characters did. I was reading book 3, Every Which Way But Dead (all the books are named after Clint Eastwood movies) when Rachel finally grew on me. Now she is a confident, mature, kick ass witch. I am going to be really sorry to see her go.
I have stated up Rachel and her vampire partner Ivy before for Ghosts of Albion/Buffy and for Ova. I ahve also used them as examples on how to build a cast using Cortex+. I'd also like to try her out in Fate.
So who is your favorite witch? What book(s) does she appear in?
ETA: Kim Harrison has part of the new cover for Witch With No Name on her site today!