1. In Normandy : the memorial & military cemetaries
2. In Paris : not many signs of ww2 there, the town was quite preserved (thanks to a german officer who refused the order from Hitler to burn the city down on retreat). There may be a few things here and there but you'll have to ask real experts.
About Germany in don't know, but I can tell you this about ww monuments :
Two things really freaked me out and made me realise what those two wars meant when i was a kid :
- military cemetaries in Normandy, with endless hills covered with simple white crosses.
- the ossuary in Douaumont, near Verdun, town where took place one of the 3 deadliest battles in History (France vs Germany, ~ 850.000 casualties). It's WWI, not II, but it simply makes you get it.
Wiki says about the ossuary in Douaumont : "The ossuary is a memorial containing the remains of both French and German soldiers who died on the Verdun battlefield. Through small outside windows, the skeletal remains of at least 130,000 unidentified combatants of both nations can be seen filling up alcoves at the lower edge of the building."