Kartana is so cute, it reminds me of when I used to be able to do origami...I bet Kartana can deliver a serious paper cut!
Personally, I like Celesteela most. Who wouldn't want a pet rocketship that could also function as a feng-shui appropriate dry bamboo arrangement?
I'd have to go with Xurkitree. I didn't care for it much at first, but it's design has grown on me over time.
My favourite is Nihilego, there's just something really cute about it. I fell in love with its design the moment it was revealed and it made me very excited to see more of the Ultra Beasts. Pheromosa and Xurkitree are also two of my favourite Pokémon. I like the rest a lot too, I think they're the most interesting and unique looking set of legendaries to date.
I've got to say Xurkitree. I love its design and it's got an adorable battle animation. I've got a soft spot for wiggling electric cable trees.
I can't really choose one. The only one who's design I like is Guzzlord, but I hate the fact that, every ****ing time, it's always the big, massive tank design that ends up being **** while ****s like Pheromosa get to be overpowered.
Xurkitree is one of my favorites as well, it's so wiggly! <3 But I do use it in competitive battle, and I love its Tail Glow/Thunder combo. With Beast Boost it can become a really powerful sweeper XDXD
Hmm, probably Buzzwole and Guzzlord, is purely design wise tho since I've never actually used a ultra beast before.