Help us (24/m) decide what Eastern European City to visit

Hi Reddit!

We're 3 decently travelled uni students (24 y/o, male) and are planning a short week's break in early June. We're a social and curious bunch, and instead of visiting significant landmarks or flashy nightclubs we'd rather experience the local culture, its people and food, and drinking. It doesn't have to be unique, pretty or anything per se, it just has to be good fun (and perhaps not too expensive).

Right now we're considering the following places:

Romania: Timisoara, Constanta or Cluj Bosnia: Sarajevo Serbia: Belgrade Lithuania: Vilnius

Do any of you have any experiences with these places? any advise? or perhaps other suggestions? any input would be most welcome!

Cheers!

PS. We've been to the Czech Republic, Hungary and Poland before, although any tips on those are also welcome :)