A different German unification (even if we can must take the POD to before the 19th Century) could make another city the German capital, perhaps Frankfurt due to its "parliament" or other city in Franconia/Rhineland region. Due to its confederal nature, one city in the geographic center of the country could be elected capital as a symbolic comprimise between the member-states (like what happened to Canberra in Australia), without really reducing the significance of Berlin or Vienna. From a Medieval POD, depending on the dynasty that "unifies" the HRE, we could see a capital somewhere else than Berlin.
Same for Italy, if the Roman Question remains unresolved and the Kingdom fails to secure Rome (not that likely, I believe). The seat of government might remain in Florence, even if there is a claim to Rome.
Russia also could also exist with a capital somewhere else if the Tsardom of Muscovy fails to rise (Vladimir comes to mind, but perhaps Kiev, if it avoids the Mongol onslaught).
China is another good example: it has had so many capitals throughout its history that the selection of Beijing could be butterflied away if successive dynasties become consolidated in the same city (Chang'an? Nanking?)