I would choose either Czechia or Slovenia, I think. I always admired them for being most developed Slavic countries, and at same time are blessed with beautiful landscapes throughout and rich culture similar to Poland, so at same time I think it wouldn't be such big change to move there.

But this is hypothetical. I would not want to leave my home country.

Well Czech are realy developed nation. On the other hand Slovenia has seriously stagnated in past 4-5 years so if someone would go to Slovenia for economic reasons then he is toasted. ;D

Hypothetically? Moravia, definitely. The reason is obvious – Moravia, Moravians and their language are the most similar to Slovakia, Slovaks and my language of all Slovakia's neighbours.

Thats cheating! ;D Anyway is there even any serious difference between Czech, Moravian and Slovak language?