Good Morning from Germany:
Before you insert your card into the ATM:
Check the access of the credit card if there is a external reader "sticked" on the ATM (Pishing of Credit Card Datas and PIN) - especially in Eastern and Southern Europe but also "safe" countries like Germany!
Use more ATMs in lobbies of banks who have cameras monitoring over the places.
And always take your receipt and check your daily credit card balance by internet.
Most ATM accept VISA and MasterCard. Amex is more limited to some chains and Diners is very rare.
Amex offers Traveller's checks on a card. Will cut loss for worst case and is safe and will be replaced.
Most bankcards showing Maestro are all accepted all over Europe.
Have a nice travel.