Having never vacationed in either city, I would rather go to Paris. I know what the Eiffel Tower, is along with lots of other French landmarks, like the Louvre (where the Mona Lisa is).
I don't have any idea of what's in Prague.
I would say Prague if you can get by with the language.
But if you do not speak Czech but do speak French, Paris might be the better choice.
I think Prague is better as Paris is very big, very overwhelming and a lot more expensive.
Paris is full of annoying Africans and is expensive. In Prague is many landmarks but they aren't so famous
I sure select Paris, and go Eiffel Tower, if select Prague can later tell "yea i was in Prague and visited umm hmm... it was nice place anyway, sunnyday is it?"
Both
Both are well worth visiting. Toss a coin.
