Favourite Gaskell longer novel and why

Which is your favourite of Mrs Gaskell's longer works and why?
These are the options:
Mary Barton (1848)
Cranford (1851)
Ruth (1853)
Biography of Charlotte Brontë (1857)
North and South (1855)
Sylvia's Lovers (1863)
Wives and Daughters (1866)

My favourite is Mary Barton with Wives and Daughters as a close second. Mary Barton is filled with life and written so fairly and with such insight, yet gentle humour pops up in the darkest passages. I read it at a gallop because I was so caught up with the story and my pulse quickened when reading the section concerning the trial. Much of the book is very sad and Gaskell has written it in such a way that the reader comes to know the characters very well.
I love the characters in Wives and Daughters and frequently laughed out loud at speeches of Mrs Gibson - such an enjoyable book and again written with so much insight.

I have read North and South, Mary Barton, Cranford and Ruth. They are all good. I liked North and South the most I think.It was state of the nation novel: rich vs poor, masters vs men, industry vs gentry, cities vs countryside. It is one of the few industrial novels. I liked the way that intelligent, working class men like Mr Higgins were allowed to put forward their own points of view in their own words. It seemed like that anyway. I think Elizabeth Gaskell is a slightly underrated author. Sometimes she is a clumsy and intrusive narrator, but her character portraits are so good, as is her dialogue.

The only author who I think was her equal at character portrayal and speech was Anthony Powell, who wrote the Dance to the Music of Time series. I read Ruth, who the heroine of a book of which was young Ruth, a very unexceptional, fallen young woman, but the character, Mr Benson, nearly took over the novel. He was some non-conformist lay preacher. It was like Elizabeth Gaskelll transcribed a tape recording of what this man was said. How did she do it? In Cranford there was a lady called Miss Matty Jenkins. She was so well drawn, she must have been a real person. I understand she was based was on Gaskell's aunt, who brought her up.