I enjoy history as well. I agree that we would not have been speaking German but the damage the Nazi's did could have been much much worse.
Their economy was replenished by creative pyramidal methods such as, "I conquer you and you will work for me", "I conquer your country and your resources are mine" or "I borrow money from you and I won't invade you". Very complex, I know.
Their military technology and scientists were used to advance the US into the space age and our military into jet aircraft. The Luftwaffe already had jets albeit very few. V2's were evolving. They were close to an atomic weapon but ran out of time. etc etc..
They initially had control of the channel until the Polish and the British had broken the Enigma code and the British and the US had improved/developed sonar and radar technology (the birth of Raytheon btw).
Anyways thank God the Allies kept constant pressure on Germany which forced them into a series of strategic blunders (Stalingrad) because if not things could have been much worse. We definitely would have known how to speak some German. Luftwaffe. Blitzkrieg. Kindergarten. Bier. Hamburger.