Alright, so I've been playing through Avalon, and I've got to say, second to Dragonspyre, it's probably my favourite world. Not just because I love medieval fantasy, but that's definitely a contributing factor. The story is a lot like a sequel to The Once and Future King, with King Artorius being King Arthur, and the Sword of Kings being Excalibur. But the one thing I love the most, is all the Monty Python and the Holy Grail references. It's my favourite movie, and it made me really happy to see the NPC dialogue nodding to it. My sides still hurt from the pomegranate quest.
I love those references as well - plus the Iron Maiden-inspired quest names and the Nine Princes in Amber-inspired Amber and Logres Knights (and possibly Mirror Avalon as well).