Where can you not go with your EU passport?
Currently, all countries accept EU passports. However, if you
have a stamp from a country B that has bad relations with country
C, or vise versa, the country C or B may deny you entry. Example,
if you enter Israel, then you cannot enter Iran or some other Arab
nations using that passport. Also, if you enter Iran or those Arab
nations, you may be denied entry when you go to Israel.