The War of the World
I have read loads about WWII, and a fair amount about 20th century history, but this got me to rethink a lot of it. He is perhaps too focused on economics and there were a surprisingly large number of typos (though I got the gist). His sense of humour certainly helps things, and he doesn't pull punches when he thinks someone (or some institution) failed. Overall, it is definitely well worth the time.
