If this thread unnecessary or doesn't belong in this section, then close/move it. (One Piece general? or Anime?)
Anywhere, the question is in title.
My favorite is probably either the Arlong Arc - great fights (methodical, hard won fights with awesome cheography and logical defeats without any asspull), awesome and engaging story, earned sentamentality (we see the affects that Arlong and poverty have on Nami and her village several times), and great cinematography and posing (seriously, Oda knocked it out of the fucking park with this one. The Nami crying "help me luffy" scene, the "which one of you is Arlong" scene, Luffy's defeat of Arlong, his stand on top of the building, etc. Probably the best shounen arc in my opinion.
My other favorite is the Skypeia arc - you gotta binge watch this one. It's great, and it shows how well Oda plans ahead, and why One Piece belongs to the Epic genre. It's so good, and it's great. I can't describe it well because it's been like 3 years since I've watched it.
This will be very controversial, but my least favorite arc is Ennies Lobby - The powerups felt forced to me (like as if Oda ran himself into a hole and didn't know how they would defeat the CP9, or he didn't feel like structuring out the order of the fights like he did with the Arlong arc), and more importantly, the sentimentality with Robin was underwhelming.
Like, I didn't gel with it. At that point, Robin was with them for the Skypeia arc, and the Davy Back Fight Arc and Jaya Arc. You know how you guys criticse Oda for not showing Robin that much? Well guess what, that - along with the fact that we don't see that much range in emotions and interactions with Robin and the rest of the crew (she usually has the same demeanor and the interactions are limited, and very basic) make it hard to feel engaged.
Like, with Nami, we see her when she's happy, when she's irritated with the crew, when she's greedy, angry, struggling, etc. We see range with her, which is why the sentimentality was earned in the Arlong Arc.
But Ennies Lobby? That felt like Fairy Tail to me.
What do you guys think? Sorry if I'm repeating old and tired arguments; I only got back into the One Piece section here just last month, before that it was a couple of years. There are things I might have forgotten about.