A different century
Any scenario that keeps Hitler out of power results in a complete re-write of the rest of the twentieth century. In difficult economic times, people will forfeit many liberties for the sake of stability. The world entered a serious recession in the twenties (Europe) and thirties (U.S.). For the first time in centuries, the American frontier was no longer available as a "relief point" for those in dire straits in Europe and the eastern U.S. The Soviets took Russia; Mussolini took Italy. Roosevelt was warned by his advisers not to run for president unless he was ready to assume the role of dictator. A month after taking office, dictate he did. In a land founded on the basis of freedom, Franklin Roosevelt issued an executive order to outlaw gold. Gold coins would no longer be legal tender. Any citizen with more than $100 worth of gold coins could be prosecuted for hoarding, a provision that would be relieved in 1954.
Now, look at Germany. Just as Roosevelt revived the U.S. economy with the WPA and an expansion of the infrastructure, the same would happen in Germany. Somebody other than Hitler would have lifted the economy by pumping up the military industrial complex (as Hitler did).
There is one thing of which we can be sure: the holocaust against the Jews would not have happened as we remember it. Sure, there was anti-Semitism, just as there was racism in America. But the level of hatred that motivated a country to execute millions on the basis of ethnicity just would not have emerged, not in such a developed country.
Following the American example, the Germans would have established controls on the banking system, regulating a business sector that (for historical factors from earlier centuries) was largely Jewish controlled. Control the economy, control the Jewish businessmen, control the growth of anti-Semitism.
So, the late thirties and early forties see a world lifting itself into economic stability by building infrastructure and the military-industrial complex. Now for the dark side.
The United States, Germany, France, Britain an others would be working on atomic technology. The work would be secret, known only to few. The people making the political decisions would not know about the bomb, only that the military is very over-confident about winning any war.
Should tensions arise, and we must not leave out China, Russia and Japan, a belated World War II might ensue with atomic bombs (perhaps nuclear warheads) in its early stages. As a result, more people are killed than were killed in OTL: more Americans, more Germans, more Russians, more Jews.
Now, i have read scenarios for a stable Weimar Germany. What does everybody else think?