Chris Riddell is a British illustrator/author whose books often seem to turn reality on its head. He has a zany sense of humour and immense creativity in his books. He works closely with Paul Stewart on several series of novels for primary-school-aged children, but he has done picture books and the Ottoline books by himself. The third Ottoline will come this year.
Two of his picture books that are fail-proof with children are The Emperor of Absurdia and Mr Underbed. Both of these are full of amazing imaginary creatures that appear to be so friendly that no child would ever be scared.
There is minimal text, but detailed illustrations with plenty to look at and wonder about... such as umbrella trees, sky fish and dinner coming before lunch.
If you want to walk around smiling all day go to Chris' website and read the section about him and then go into fun stuff and watch him draw while he chats.