The Twits, Roald Dahl
The Hobbit, J.R.R. Tolkien
The Handmaid's Tale, Margaret Atwood (I read this, my first Margaret Atwood book, at school when I was 16 on the advice of my lovely English teacher, Mrs Nelken. This stood out for me as when I saw Margaret Atwood at the Queen's Hall last week she spoke about putting her high school gym into The Handmaid's Tale.)
The Wind In The Willows, Kenneth Grahame
The Lost Continent, Bill Bryson (I know this is technically the first TWO lines, but you can't NOT have the punchline to that joke)
Northanger Abbey, Jane Austen
A Christmas Carol, Charles Dickens
The Secret Garden, Frances Hodgson Burnett
A Prayer for Owen Meany, John Irving
And then later from the same book, a description which had me begging my parents for a baby pig that I would name Wilbur:
"As she approached her chair, the carton wobbled, and there was a scratching noise. Fern looked at her father. Then she lifted the lid of the carton. There, inside, looking up at her, was the newborn pig. It was a white one. The morning light shone through its ears, turning them pink."
Charlotte's Web, E.B. White
These are in no particular order, just the order in which I picked them off my bookshelves, lovingly caressed their worn pages, gave them a hug and replaced them on the shelf.
I also found this series of quizzes on opening lines of all sorts of books, which kept me occupied for far longer than it should have today.
*I have tried many times to pin down my one favourite book, and I just can't do it. There are too many that I love far too much to be able to pick one over the other - it would feel like a betrayal.