I like the ones you find boring (but not the corporate Memphis ones) - money is a serious matter, so it's IMO supposed to look serious and a little boring.
I feel like banknotes is one of the few common-places that EU could convey some sort of "shared vision/purpose" that is largely missing in general. From this perspective "boring" as in buildings etc are not very good options as they do not convey anything positive, and make it look further "cold and distant" from people. While options like F show a vision which europe could aim towards.
Of course then, on the other hand, the boring options are in this sense the most honest ones.
Of course then, on the other hand, the boring options are in this sense the most honest ones.