What would you say is are great/good aspects of your least favorite arc? It can be be characters events, attacks, artwork, etc.

In Stars, I liked the beautiful artwork of Galaxia's base. I also liked the idea of the Galaxy Cauldron and I liked that Naoko used things from actual astronomy as inspiration: 
(Sagittarius Zero Star = Sagittarius A*; Galaxy Cauldron = Supermassive Blackhole)

My least favorite arc is Black Moon/R. What I like about it is that it introduces Sailor Pluto and Crystal Tokyo, and the liking of Crysatl Tokyo has nothing to do with UsaMamo confirmation no sir. I also don't mind Chibiusa, so I guess I like that's she's introduced there as well.

Fine, I'll pick Stars. I like Galaxia's portrayal in that one and the scenes of the other Shadow Galactica Sailor Animamates that didn't appear in the 90's anime, I find their slight mythology symbolism interesting.

I like the scene where Queen N is defeated at the end of the Dream Arc and everyone transforms into their princess forms. I'm looking forward to that scene in SMC.

I thought the art in the Dream Arc was as beautiful as ever, I liked the Seshi getting their new power-ups and the brief look at Rei and Ami's pasts. But overall it had the least interesting villian and climax I feel.