Well I don't have many arcs that are 10/10 since there's always flaws with arcs. I'll just list arcs that are equal to 9 or above out of a 10 rating scale.
One Piece
1.
Marineford (very sad deaths and overall an entertaining action arc)
2.
Dressrosa (I'm considering to put this arc over MF but I will wait till it's done. This arc has everything)
3.
Enies Lobby (Robin's backstory + Sogeking + Luffy/Zoro/Sanji epic fights)
4.
Sabaody (Introduction to supernovas and a very satisfying OHKO punch from Luffy against a certain person
)
5.
Water 7 (Awesome arc and drama)
Hunter x Hunter
1.
Dark Continent - (This arc is no where near being done and all we've been getting is some mind-blowing setup. I have high confidence that this arc will probably be the best HxH arc. The Kakin princes introduced is amazing and seeing Ging's & Pariston's character interactions is very entertaining and written well.)
2.
Chimera Ant - (just like Chapter Black from YYH it discussed interesting themes and had the most entertaining fight I've read that's well written as well.)
3.
YorkNew - (Action packed and the phantom troupe were kick ass)
4.
Election - (People don't like the politics of this arc but I enjoyed it. The Zodiacs are an interesting bunch of characters that I love. Ging's final words to Gon was excellent, personally I think those words can literally apply to anyone and it's so true.)
5.
Hunter Exams - (The arc that started this amazing series and the obstacles just to get their license was enjoyable to watch.)
Toriko
1.
Cooking Festival (It had amazing fights and more important mind-blowing world building at the end, not to mention Toriko's character development was nice)
2.
PAIR (Easily one of the weirdest shonen arcs but the entertainment value on this was high. I already miss the problem child of the 8 kings, Bambina!)
3.
Meteor Garlic (Man, this arc was pretty arc. The gourment casino showed the dark side of Toriko where people gamble for narcotics (food) and Coco was awesome)
4/5.
Regal Mammoth/Century Soup (Action packed arcs with interesting introduction to characters and new environments)
Yu Yu Hakusho
1.
Chapter Black (Introduction to best shonen villian I've ever seen, Sensui. With interesting themes dicussed as expected from someone like Togashi.)
2.
Dark Tournament (Action packed arc with an awesome villain, Toguro)
Fairy Tail
1.
Tower of Heaven (Erza's backstory)
2.
Phantom Lord (Lucy's backstory was nice and actually made me enjoy her character a lot more. Her father is scum. )
3.
Oración Seis (Based Wendy)
4.
Battle of Fairy Tail (Based Laxus)
Naruto
1.
Itachi Pursuit (Epic and it should be one every Naruto fan's top arc list)
2.
Sasuke Retrieval (Action packed and entertaining)
