What's the best way to map PC keyboard modifier keys to Mac keys?

A PC has 3 modifier keys for keyboard shortcuts: control, the Windows key, and alt. A Mac also has 3 keys: control, command and option. What's the best way to map one to the other?

I dislike how some shortcuts which use control in Windows and Linux, like ctrl+c for copy, instead use alt in Mac OS. This causes me to occasionally use the wrong ones in Mac OS, and occasionally use the wrong ones elsewhere after using Mac OS for a while. Should I swap alt and control in Mac OS?