Mine is the Bloom from Torment: Tides of Numenera. I love the fleshy bits. I love the everyday gruesome horror becoming an everyday thing for the people who live there. I love the literally organic surroundings. It’s just by far my favorite location in any game ever. :)
Daresso, King of Swords, music definitely make it 100 times better, though that level is also cool by itself.