Moira is VERY likeable, not a fuck does she give. She is quick witted and has a big heart and a big brain.
June is selfish but smart enough to engineer what she wants. What she wants might benefit other people, but it's not really for their benefit, it's for hers.
I think the strength of the book, when I read it about a million years ago, is that June and Mrs Waterford are quite similar in nature. Mrs Waterford believes herself to be strong because she has power, but in the course of the story she recognises that June is far stronger and resourceful than she is. And the Mrs Waterford is angry and a lot of her anger is with herself. But, both women are, at heart, selfish.
I loved that because usually female characters are just maternal, or just sexy, or just kind, or just fixers or just fuckable.
Moira is my favourite because I'd like to have a smart, kind, funny, loyal, sensible friend like her. Who wouldn't? (with apologies to my SKFLSFs)