compton
Gyor-Per and Pecs Pogany in Hungary
Pécs is not functioning as a commercial airport (and is too small for an A-320) while Győr is too close to BUD (60 mins on road and only slightly more by train). The next logical option in Hungary would be Sármellék(-Balaton) IMHO.
Not considering the distance from existing Wizz destinations a lot more EE airports could be added to the list: Podgorica, Tivat, Mostar, Maribor, Rijeka, Osijek, Ostrava, Rzeszow, Krakow, Lodz (again), Pula, Zadar, Sarajevo, Bratislava, Lviv, Odessa, Pardubice, Karlovy Vary, Tirana, Pristina etc etc.