I have just re-read this for about the fourth time, and I still think it is the best overview: balanced, well-written, with a nice mixture of grand strategy, tactics, personalities, and personal narratives - from both Allied and German sides (and French civilians, too); plus a healthy dose of personal opinion, but not in an obtrusive way. And still it works, which is quite something!
The book is based on a lot of sources, including many interviews with survivors by Hastings himself.
The landings in Normandy on June 6, 1944; the frustration of the bocage, Montgomery's grandstanding as well as his qualities, comparisons between the various armies; it's all there, but it never seems to stop the sweep of the story, it all is beautifully meshed into a coherent whole.
I will buy any history book by Hastings, without reading reviews or opinions by others; and I still think this is one of his best.