My ratings:
Romance Dawn: 7/10 - Intro stuff
Orange Town: 6/10 - More Intro stuff here
Syrup Village: 6/10 - Meh who cares
Baratie: 7/10 - Not bad
Arlong Park: 9/10 - Great arc. Loved Nami's storyline and the Fishman pirates were great
Loguetown: 8/10 - Good stuff, this is where the journey really began
Whiskey Peak: 7/10 - Pretty good stuff here, more of a setup arc for Alabasta
Little Garden: 7/10 - This was ok
Drum Island: 5/10 - Didn't like it, don't care about Chopper, shit arc
Alabasta: 10/10 - This is where One Piece really started for me. Great storyline with Vivi, Zoro vs Mr. 1 and Luffy vs Crocodile were both dope fight scenes
Jaya/Skypiea: 7.5/10 - Pretty good stuff, Enel was cool, good history with Nico Robin and poneglyphs
Foxy: 6/10 - Trash arc who cares
Water Seven/Enies Lobby: 10/10 - Great stuff, Franky was cool, everything with Usopp/Luffy was dope, Zoro vs Kaku & Luffy vs Lucci were both EPIC as fuck, Nico Robin's storyline was amazing I love her and wish Oda would do more with her
Thriller Bark: 8/10 - Kuma and the final battle with Moria saved the arc at the end. Good stuff with Zoro and Ryuma.
Sabaody: 9/10 - Great supernova stuff and Luffy attacking the Celestial Dragon. Awesome stuff with Kuma.
Amazon Lilly: 8/10 - Loved all the Boa Hancock stuff
Impel Down: 8/10 - Great escape and rescue arc, nice confrontation between Luffy and Blackbeard
Marineford: 10/10 - Fuckin EPIC, Ace death scene was awesome and sad at the same time, great fight scenes, big implications for the overall OP storyline, Shanks appearance was insane
Fishman Island: 8/10 - Pretty good stuff, Sanji's parts were hilarious and the final battle was ok
Punk Hazard: 8/10 - Great showcase for Law, Smoker looked good, Caesar Clown was cool
Dressrosa: 8/10 - Doflamingo is the fuckin man, Gear 4th was lit
Zou: 8/10 - This was pretty good, loved the history being told
Whole Cake: 8.5/10 - Disappointed with Sanji, but overall a great tea party and great Katakuri/Luffy fight, Snakeman was lit, good showcase for Capone, Big Mom was fine just a little too much wedding caking
Wano Kuni so far: 8/10 - Kaido has been a little disappointing as Oda set him up as way more intimidating pre-Wano, but the storyline is not bad at all, loving all the characters so far, not too big of a fan of Oden injuring Kaido he's a shit character, loving Kaido's commanders, this is setting up to be a 10/10 arc in the end, we should be getting a lot of greatness coming up