Don't care about Naruto, but I'll never see the appeal of One Piece. The 'epic' fights aren't even that. The art is terrible. The cast sucks (minus a few great ones here and there). It's not funny, it's stupid. Hell the Marineford arc is supposed to be this uber epic arc but the only thing that stood out about that was WhiteBeard. And all he did was shout and swing his blade to create shockwaves. The Shinchibuki and the admirals did nothing there except Akainu and Ace's death wasn't even emotional.
But I guess if you like nakama, shouting, over exaggerated facial expressions and slapstick humour, you can give it a chance.