Oh, favorites are hard. Housemate and I have been working our way through a bunch of mostly White Mountain puzzles, mostly on the theme of “pretty room with books and comfy seating and a couple of pets”; the current one in progress is a (very much fantasy version of a) Rare Book Store. The ceiling in it is particularly lovely: https://www.reddit.com/r/Jigsawpuzzles/comments/1bd5z6t/rare_book_store_white_mountain_1000_artwork_by/