EU already have capitals, Strasbourg and Brussels. Millions were spent on those cities in infrastructures for the EU instituitions.
Rome. Or maybe Vienna. Or maybe Aachen? Definitely not Paris nor Berlin.
Aachen
Charlemagne will return!
Carthage
-signed Hannibal.
Or, you could do what Australia did when it united in 1901 - agree on a parcel of land, possibly on the border of Germany and France, which becomes the EU Capital Territory, then build a new capital there.
Challenge Mode : Play WoW like my disability has me play:
You will need two people, Brian MUST use the mouse for movement/looking and John MUST use the keyboard for casting, attacking, healing etc.
Briand and John share the same goal, same intentions - but they can't talk to each other, however they can react to each other's in game activities.
Now see how far Brian and John get in WoW.
Berlin or Moscow.
Turkey?
All they have to do is call the Germans racist and its in the bag.
Brussels is the capital. It is also conveniently located near the largest EU population hubs and is well connected by rail to other areas housing political agencies and departments.
No need to move it.
What should be avoided is the concentration of non political offices and agencies there.
Like those dealing with education, healthcare etc. Those should be spread across Europe, especially in poorer regions to attract skilled labor and capital investment.