We bought this book for our 6-year-old son last Christmas and he loves it. It's just so much fun to share a book with him that we remember fondly from childhood and find that it's still as enjoyable as ever for all of us.
This format, where you get one story per book with lots of excellent illustrations is great for younger readers as well, as they can begin to read for themselves.
We've since bought "Paddington in the Garden" and "Paddington at the Zoo", and I'm sure there will be more to follow as well.