Good long Arthurian mythos based novels?

I've been playing a lot of Tainted Grail. And I'm looking for books in that kind of style. A re imagining of the Arthurian Mythos with a unique theme.

Like Tainted Grail feels a tad Lovecraft at times and Arthur's coffin looks like something straight out of Gigers style.

Please, I beg of yall. Give me something good.