Well, most people correlate the French Resistance with De Gaulle, who was an ally of US and the UK, and therefore Day-D as the key battle makes action in the lay (non-french) people understanding of the liberation of France.
Outside of that, I think that USA role in WWII is underrated by some people ("tankies" beig only a part of them). WWII was not the Allies vs the nazis, it was the Allies vs the Axis. The USA was the main actor in the defeat of Japan and its role on the defeat of Italy (even if it was the weak link of the Axis) is appreciable. The role of the brittish in the war agaisnt Germany, specially in 1940, should neither be underrated.
Even if you consider only the battles fought by the western allies, you don't need to consider the Normandy landing the top battle.
Which one would be for you?
Seriously. There has been a contrarian trend to go too far in the other direction of Western Cold War propaganda and act like the Soviets were these sole good actors responsible for an Allied victory while the Western Allies just sat on their ass. This conveniently ignores that they literally TRIED TO BE ALLIES WITH NAZI GERMANY before circumstances pushed them to the Allies (automatic loss of any moral high ground), and they only contributed to the fight against Imperial Japan at the 11th hour once it was clearly over so they could greedily gobble up some territory for themselves...
not to mention that the Soviet's successes never would have happened without western aid
