Bad hygiene is the worst immediately, for longer term relationships bad character comes second. Although I really don't like it, if I really like her I can tolerate bad (if not really horrible) breath if I see it's not due to bad hygiene. I don't like girls always complaining and bickering, but if they are intelligent and strong and they don't do it to bicker, I like frank, even blunt ones, I had one like that, she told me what she thought even if I could not like it, but she never used those things to argue.
I've got no problems with women with kids, although their kids usually don't like me instead.