I have been delving into to Ultima series recently. I played Ultima Underworld a few years ago for the first time and really enjoyed it. The level of interactivity and freedom the game gives is mind blowing for the era.
I have now started the main series and have began with Ultima IV. It is really quite a unique CRPG. It's not just another RPG about delving into dungeons and fighting monsters, although there is plenty of that, it is a journey of spiritual enlightenment. The main goal is to embody the eight virtues of the avatar which entails a huge scavenger hunt of talking to people, learning about the virtues, finding runes, gaining knowledge, and of course fighting plenty of monsters along the way. Because even the avatar needs XP and gold of course.
It's a slow process, but I am having a good time with Ultima IV so far.