Having read several biographies of Dahl (and his two autobiographies) I cannot really escape the impression that he seemed a bit, well, unlikable in some ways, especially to women.
However, having grown up on his books, I can say that he's provided (and is still providing) a sterling service of teaching kids that all is not sweetness and light in the world and humour is not necessarily all about slapstick but is sometimes darker and more interesting. For that I salute him.
(My favourite, or at least the one that made the biggest impression on me) was the BFG.