Fiction

The Gruffalo by Julia Donaldson & Axel Scheffler
It's the 10th anniversary of The Gruffalo this year, in which time it seems to have become a classic of young children's literature. I've never read it before though (unsurprisingly, considering my age). It certainly lives up to its reputation however.
(Like most good young children's books, it's also poetry, hence the additional tag.)