In the fiction realm, War Of The Rats by David Robbins is very good. I generally only go for the non-fiction stuff, but this one was well worth it. He does a great job of pulling you into the famous sniper duel between Vasily Zaitsev and SS Major Heinz Thorvald. Good mix of history and embellishment. (sounds like our public schools...)
As for the "real" stuff:
1. Rommel Papers (if you're a N. Afr nut) - Unusually good read for memoirs.
2. A Bridge Too Far - of course. Ryan is great, IMHO.
3. Achtung! Panzer - Guderian's work on armor. Neat stuff.
My 2 cents.
Preacher