I don't want to advertise one method - but I think a DRM free game should be purchased via a non-tracked method. Thus I would never use PayPal ... so currently there is no acceptable payment method from my point of view.
In Europa paysafecard is popular and is a prepaid method available in several stores - without account or anything.
If I overlook something please give examples - but currently this is the only acceptable payment via web (and I know other people thinking the same) - and thus I would be happy if it can be supported so I (and others with this preference) in return can support those extraordinary developers here at itch.io and the good service itch.io provides.
A second thing is that it may require a payment in EUR (the European currency) ... and currently I know only one gaming platform providing this payment method and EUR prices at all - all other seem to be US centric - understandable, but problematic.
Many thanks in advance for your help.