Considering not everybody might be finished yet, please put your description in spoiler tags if it reveals anything. The name itself shouldn't really be a spoiler, so no need to spoiler tag that. Well... Except maybe the one where you fight the final boss, but I think that one you can describe without specifically naming it.

For me it's hard to choose between ::: spoiler Verdania and Choral Chambers
Both have such an awesome atmosphere (and music) because they portray something that was there in the past but only glimpses of that grandeur can be seen now. It's fascinating to see how much storytelling they do through the environment and game mechanics instead of telling you directly. And of course the background art is great as well. The lush green in Lost Verdania reminds me so much of the Greenpath in HK, but it's not just a copy, it's its own thing with the water ponds and thorns
:::