There's a game called Deathlord that was only made for the Apple //e computer and I think the Amiga, and it's honestly better than Ultima 1-6 were, in similar style, with an oriental theme, and devious puzzles and dungeons.
The world is over 1 million tiles in size, the combat is very enjoyable, much exploration, puzzles, everything you could ask for.
Here's a link to it on the Underdogs site: http://188.8.131.52/game.php?id=4848
It's honestly better than any other party-based RPG that was made in those days, It's got some quirks, but once you figure the game out it's actually got quite an enjoyable interface and control scheme.
You will need the apple emulator if you wish to play it, I use applewin, it's the best one: http://applewin.berlios.de/
I'd also recommend helherron (note that the linux version of helherron is MUCH more stable than the windows version); there are many others but these 2 are some of the least well-known and also the best, and I have a feeling most of the people who visit this site will have played 90% of the party-based RPGs that are out there.
But Deathlord is a true hidden diamond, atmospheric, very, very good. I rediscovered it just a bit ago, with very fond memories from around the 1980s playing it as a kid; it's every bit as good as I'd remembered.