. . . I think my favourite, after the Might & Magic and Eye of the Beholder series, was Ultima Underworld 2. I thought the first three levels, (Britannia, Killorn Keep, and the Ice Caves) were excellent, as were levels 5, 6 & 7 (Scintillus Academy, the Pits of Carnage, and the Tomb of Praecor Loth). I didn't enjoy level 4 (Talorus) or level 8 (The Ethereal Void) as much, though. Also, it had (for me) the disadvantage that you were playing a single character rather thatn a party.
Of the available characters, I found the one that suited my style of play best was the Paladin, and worst was the Archer – Stålhand please note!