> At least here in Europe MasterCard and visa are the only options. Amex and Discovery are really unusable here.
Depends on the country!
Amex is accepted in many places in Germany these days (though you definitely still need to carry another card, so it can't be your only card).
And Discover and Diners Club are actually the same network, so in the European countries that have strong Diners Club acceptance, you can usually also get by with Discover. (No idea about how good the exchange rates are, though; those of Diners Club in the other direction are atrocious.)
Depends on the country!
Amex is accepted in many places in Germany these days (though you definitely still need to carry another card, so it can't be your only card).
And Discover and Diners Club are actually the same network, so in the European countries that have strong Diners Club acceptance, you can usually also get by with Discover. (No idea about how good the exchange rates are, though; those of Diners Club in the other direction are atrocious.)