Worst possible Versailles would be seeing the German Empire completely dismembered into numerous states with varying degree's of autonomy from the Entente and League of Nations. Think of what happened with Austo-Hungary; the states are completely dissected, with annexations and messy territory wars abound. France and Belgium gain complete control of the Rhineland, which becomes a Satellite State if not outright annexed and divided. Prussia looses a large swath of territory in order to nullify it's power. All these states are enforced neutrals, their armies reduced to a glorified police force, infrastructure severally crippled, and financially dependent on the Entente, who enforce all this and make sure there are no more German Reunification, backing Annexation's for neighboring states, like Denmark, Switzerland, Poland and anyone else who wanted a slice.
Now part of the issue with this would be Germany's hegemony, so a great deal of effort would be bought about to break the idea of a pan-Germanic state. Prussia will be blamed for most of what had happened, in an attempt to turn the German states against the central Kingdom. Others will be given a new ethical identity, such as 'Bavarian' or 'Rhenish', and be played off one another by the controlling powers to create competition that would keep the states so busy they don't expand outwards.
Of course, this will all apart like a house made of mash potato on a rainy day depending on A) How dedicated the Allies are to avoiding a new German State and B) If they can successfully pacify Germany.