One of my favourites since I read one of his stories in English class in High School and was moved to buy a Scholastic Reader "Best of" collection. His humour has a dark edge to it that I've rarely seen elsewhere. Sort of like P. G. Wodehouse with a slightly nasty attitude. I've recently been re-reading his many short stories and starting the novels I hadn't got to.
My favourite short stories:
Tobermory
Gabriel-Ernest
The Schartz-Metterklume Method
The Boar-Pig
The Storyteller
The Open Window
Sredni Vashtar
Laura
Mrs. Packletide's Tiger

One to avoid:
The Unbearable Bassington
I've read somewhere that this story was written as a "serious novel". Clearly he was much better at humour.

Oh, Tobermory's great. I love the way all the humans are flipping out over this talking cat and the cat himself just sits there calmly, waiting for the hubbub to die down. Just exactly what would happen in real life.

Favourite quote -

- "you must be the new governess"

- "well, if I must, I must" said Lady Carlotta to herself with dangerous meekness...

The Schartzmetterclume Method.

This is quoted in my family regularly...