Best one of his books I read to be honest is "the world according to Clarkson", but they are all good.
Also 3/4 of the way through Richard Hammond's book. Definitely worth a read and his wife is a surprisingly good writer!
My favourite Clarkson books are Born to be Riled and The World According to Clarkson.
Persuit of Happyness (spelt like that!)
I'd quite to read Richard Hammond's book, have to try and get a copy.