For me there was only one choice and it was interesting to see that they touched on it in Dial of Destiny - The Spear of Destiny.
The year is 1959 and Indiana Jones still carries with him the guilt that at the Säuberung book burning ritual in the Opernplatz (Berlin), he had not killed Adolph Hitler. Undoubtedly, Jones knew he would have lost his life had he done so but, the knowledge that the Führer had gone on to commit indescribable crimes against humanity, was a heavy burden Jones had carried with him since that night in 1938…
Jones like the leaders in the West, believed that Hitler had perished in his bunker on 30 April 1945, but they were wrong. Not only had the Führer escaped but he had taken with him the Spear of Longinus - leaving behind a perfect replica that deceived the Allied soldiers when they discovered the spear at the end of the war.
Now, on a trip to Italy, Indiana Jones discovered that the holy lance - residing in the Hofsburg museum in Vienna, Austria - was actually a brilliant fake created under duress by the Italian master craftsman Antonius Magnoli for Hitler in 1942. At the same time he also learned that the Führer had not perished but had in fact escaped and thus was set the ultimate confrontation between Indiana Jones and his bête noire - Adolph Hitler