I read this book about eight years ago and absolutely loved it. Besides the Arthurian stuff of course, I liked the way Bradley had turned the legends over and wrapped an interesting fantasy around it, focusing simultaneously on the emotional flaws of the main characters and the encroachment of Christianity into the region. (And I laugh at the 1-star reviews over at Amazon.com that trash the book because it's ahistorical, as though there exist ANY Arthurian legends that aren't already intertwined with fantasy. Who cares that the depiction of the pagan religion isn't historical? _Mists_ is already shelved in the fantasy section!)
What really struck me though was when Morgaine goes to Wales and slowly begins the process of re-finding herself as a Priestess. I vaguely remember being on the floor reading those pages and them having such profound effect.
There was no sleep for me that night. Alone, I walked in the garden till dawn, and I knew already, shaking with terror, what must be done. I did not know how, or whether, alone, I could do what I had begun, but as I had been made priestess so many years ago and renounced it, so must I retrace my steps alone. This night I had been given a great grace; but I knew there would be no more signs for me and no help given until I had made myself, alone, unaided, again the priestess I had been trained to be.
(Ah...I remember now. I was on the floor at Somerset, and I had gotten this book near the beginning of my search to find my center again after a long-term relationship had imploded. I had spent years trying to be someone else, anyone else, than who I had been growing up, but after the relationship I realized that I would need to struggle to be a better person but also let go of my own self-loathing. In _Mists_ I found the same struggle in Morgaine.)
This is still one of my favorite stories of someone who threw away their chosen path only to fight their way back. Yet Morgaine is still human, and we already know how her story ends, and it is a train wreck that you can't avoid. She's going to become one of the most hated villains in legend, but from her perspective she is trying to save her world.
The other thing I really liked is the calm Zen-like practices of Avalon. A day spent in meditation and quiet living has always been appealing to me. I really can't wait for the day my wife and I can have our own place.