I don't like the term "Roman Catholic" because it was invented by Anglicans in an attempt to claim that their catholicity is on par with ours.
To be fair, though, it isn't unheard of for an opponent-given-name to later become standard. (For example, "Lutheran" and "Methodist" are both opponent-given-names.)
I wonder how would you explain the usage of the term "Roman Catholics" in countries where there are no Anglicans. What international conspiracy would you find?
Anglicans are responsible for the English term "Roman Catholics". Other groups are responsible for the comparable term in other languages.