The rules are simple. Name one character in the Dresdenverse that fits in each category. Tell why if you want. Oh, one thing.... sex in marriage is not a given. As some married people, like myself, have learned.
F**K: Andi. While she is not my first choice; she is the safest of the top 5 or so. Lea is too scary. Lara would kill me in the course of the act. Molly is Winter Lady, ask Carlos what that means. And, as for why Andi, ask Bob what makes women great to see. We tend to agree on aesthetics.
Marry: Charity. She is the perfect home-maker. Cooks big meals and can kick butt when necessary.
Kill: I would have to go with most of the guys. Sorry, fellows, but I am straight. Thomas could get a question mark; since he seems to do open-relationships.