In countries where I never held a DL issued in that country, and in approximate descending order of least recent

Spain
Hungary
New Zealand
Australia
Cyprus
Jordan
Argentina
Iceland (got a manual, and an automatic - got a cautionary notification if could use one )
Croatia (into Montenegro and Bosnia-Herzegovina)
Germany (an automatic took getting used to)
Belize
France (drove car into Switzerland for ~1/2hr)
Easter Island (Chile)
Austria
Malta
Italy
French Polynesia (4 islands!)
Malaysia

A few times, I've returned a rental car driven on one side of the road and then picked up another car driving on the other side of the road a few hours later (mainly between Italy and MLA).

Anyone take rental cars on long or int'l ferry crossings? For me, Toulon-Ajacco, Bastia-Nice, Savona-Bastia, Bonifacio - Santa Teresa Gallura, Arbatax-Civitavecchia