Seconded. Morrowind is still to this day the game I think of when I think "open world RPG". For the time, the world was mind-blowingly massive to the extent I drew a map of where all the silt striders and ferries went so I could get around more easily.

One day, maybe the Skywind project will have it in playable form that looks good on modern computers, and then I'll be experiencing it again for sure. :)