I travel a lot and use VISA. If you pay stuff with VISA, the banks in Europe don't charge anything. But if you get money with them at an ATM, the ATM operators cahrge anywhere between $2.50 to $5.00 per transaction. Then my bank charges me around $3.00 per transaction too.
If you pay everything with VISA, these charges are almost non-existent, and exchange rates are on day of transaction.