I assume you're talking about the Balkans in the last millennium. These are PODs I remember putting up myself:
1) Bulgaria doesn't start the 2nd Balkan War.
2) The Turkish advance into the Balkans is stopped in the mid 14th century.
3) The pro-German government in Belgrade is not overthrown in 1941, so there is no German intervention.
4) Austria doesn't lose its 1737-1739 war with the Ottomans.
5) Vienna falls in 1529 (not a Balkan POD, but has effects there).
6) Vienna falls in 1683 (not a Balkan POD, but has effects there).
7) Suleiman doesn't die at the Battle of Szigetvar.
8) Russia gets the Romanian Principalities at the Treaty of Bucharest (at least I think I put it up).
9) Greece joins the Crimean War on Russia's side.
10) Napoleon III lands a Hungarian Legion led by Lajos Kossuth on Austria's Adriatic coast during the Austro-Sardinian War.