WWII is a topic of interest for me, so I have read several books (fiction and non). One of my favourites is
The Storm of War by Andrew Roberts: I like that the author focused on periods, battles and issues beyond US, UK and Germany. Includes a good focus on the Soviet Union and other parts of Europe, as well as the run-up to the war. Only downside: politically and ethically, I disagree with his conclusion that use of nuclear warfare by the US was justifiable.
It is still a good read.