A couple times I've thought have getting a little "meta" in my music choices, and replacing some of the UO tracks with music from the ".//Hack" games and anime.
After all, while console games, the games are emulations of playing a future VR MMORPG, that in many ways corresponds as its world's UO. And 99%+ of the 3 video series (at least 2 of which were TV series in Japan) take place IN the game, via their character perspectives. They have people that are playing characters nothing like their real personas for various reasons (example, we have persons playing characters of the other sex, a character that is effectively a order guild leader, playing the game in great deal because it's the only place that she can walk, being wheelchair bound in real life), merchants (both the good and duper variety), even a wise old player or two, giving advise to younger ones - one of which we find the fate of, when the character is seen talking to a GM, telling him that the old man passed away, and he was on his father's character to pass the word to those he knew and loved in the game (and vice-versa).
I recommend watching the anime for those who play ultima - especially the "bonus" episodes after the series' end for "Sign". Music-wise, one of my favorite tracks is "Dwindled Bible" from the "Roots" series.