Not exactly faked, but the World Wars? I think the Tsarists, Soviets, Germans and Japanese largely kept quiet about their defeats but were sure to make all their victories known. Both the Germans in WWI and Japan in WWII did not believe that they had lost fairly because they did not know about their defeats.

If you just talk about fake, exaggerated numbers, there probably hasn't been a war when the numbers haven't been exaggerated at least once.