From dreaming, I experienced galaxy flooring + wallpaper for the first time and LOVED it!! I love how you're pretty much floating with the cool 3D effect
The Ivy Wall from Saharah is my very favorite wallpaper with all the Botanical-tile variants as a close second! The Dark Herringbone is my favorite flooring :3
My tastes are basic cuz my faves are the popular ones, but will still share anyways lol. My favorite wallpaper is probably the Cafe-curtain wall? Not sure though since I'm not decorating my interiors yet but I really like that wallpaper look wise... As for my favorite flooring, this is easy because I already know what this is early on in the game because I kinda want to use this in every room on my witch's house, it's the Cloud floor and I really like it cuz of it's animation, looks really cool and magical! Plus you could put a pattern/rug over it and the animation would still be there which gives of a great effect!
There are actually lots of awesome wallpaper and flooring. It honestly depends on what kind of room you're going for and how you will blend them with the type and color of furniture/wall items you used. Personally, I love the combination of underwater wall and flooring on my "Under the Sea" bedroom. It's the only time I used a set (I prefer mix and matching for the rest). It makes you feel like you're inside an aquarium or you could say that you're actually under the sea with the Ariel thing going on.
I like the cool painted and cute painted floor, they're great for adding a pop of colour. I also like the wedding curtain wall, makes for a cozy bedroom if you put up some nova lights.
I have a lot of favorites but just going to list the ones on top of my head!
The underwater set for one! I also like the pirate room floor that Gullivar gives.
The arched window and cafe curtain walls are also favorites of mine and I have multiple copies of them.
The cityscape and the one with the rain too!
The dynamic wallpapers are pretty. My favorites are the cherry blossom and stormy-night walls. Also like the manga library, cafe curtain, and wild wood walls. Hoping to find the cafe curtain eventually.
For flooring: cute-paint, sakura-wood, rush tatami, and dark herringbone.
Favorite walls: starry-sky wall and sky wall
And the favorite floors: galaxy flooring and cloud flooring
Those combos are just so mystical and I love them!