I did finally get around to reading William Shirer's The Rise and Fall of the Third Reich, and it was excellent.
Do it. You won't regret it. Great inside account not only of the war itself, but of its root causes, and the buildup to it. Of course, the fact that Churchill was a (or perhaps the) key player makes it better.
Contrast with his A History of the English Speaking Peoples, four volumes ©1956-58. I love Winnie, but God, what a plodder. Of course, he was well into his 80s when he wrote it. But way too broad in scope, and the author didn't star in the work.