Without Hitler it would have been worse
Without Hitler there would have been no NAZI victories in the elections, the National Socialist party would have stayed a bunch of fringe malcontents.
But, now you open up a new can of worms. Who puts worms in cans anyway? But I digress. The communist movement in Germany was pretty powerful, without a strong National Socialist party do the communists take power? If they do now you have a communist USSR AND a communist Germany. OUCH.
Or, perhaps the general staff launch some sort of movement of their own to counter the communist threat and Germany gets some real leadership, say a General Hans von Seeckt, or a von Bock, or and this would have been horrible for the allies, a von Manstein.
Now things will get really interesting. The Germans were generations ahead of the allies in advanced weaponry, it was only the idiocy of Hitler and his underlings that kept this technology from actually being used. Imagine a Luftwaffe with jet fighters in 1941. Or submarines that make their own fuel from sea water and never have to surface.
With professional leadership, Germany could have been a much stronger country in 1940 and their military could have been in a completely different league than the rest of the world.