While I think you framed the alternative history scenario too openly and with a very unrealistic assumption, to me it still presents one of the ultimate "what if's" of history.
I think instead of saying "what if Hilter won the war," you could asked "what if: during Operation Barbarossa, the Germans went initially south to the Russian oilfields instead of attempting to capture Moscow. Then, if successful, regrouped and then attempted a Moscow assault in the spring of 1942. If successful, the Germans may have drove the Soviets to the Urals and then perhaps killed Stalin and many of the Soviet leaders by 1943. The Soviet government would have been destroyed and perhaps never reconstitute as it existed in actual post-WWII history.
However, a Soviet defeat would not likely ensure a German victory, as D-day still would have occurred and eventually the Allies would have nukes. If Germany had not surrendered by 1945, German cities would have been potential targets for nuclear strikes, as a Soviet defeat would not likely change the US/UK's air superiority over Germany.
So, then after the Soviet Union, Nazi Germany, and Imperial Japan's defeats by 1945 (or perhaps 1946), the US would have been even more powerful relative to any other country in the world at the time. While the Chinese Civil War still would have resumed after WWII, the US could have supplied and aided the Chinese nationalists with more impunity without the fear of Russian Soviet retaliatory escalation. Also, other communist revolutions would either had to face American/British/French/...Russian/Chinese resistance or never see much backing from a foreign power."
So yeah, the world could have been much better off with Stalin's defeat, though many still would have died- just different people in far less numbers.