there both great anime, narutos fighting is more complex than op but op has a great storyline and a great range of characters also
naruto has a decent storyline, if you have been a naruto fan since before shippuden then you would understand how great the series is
so theres no saying one is better they both have drawbacks
naruto can make anyone wanna watch it, and i mean anyone and its easy to understand and it draws you in by watching the first few episodes like the kakashi training with the bells, the chunnin exam, the multiple zabuza encounters back when sasuke was good, now they have grown and its on a whole new level