This is probably really old hat and you all know about it, but as it's on the Waterstones BOGOF deal I thought I'd mention it.
DH bought this book yesterday and I read it to DD (4 next month) last night. It's a beautiful, sad and then uplifting story, elements of the Snowman and also Tiger Who Came to Tea, the illustrations are truly beautiful.
As soon as I finished it DD wanted to read it again. Highly recommended!