I voted because of its uniqueness, but characters, animation, story, chicks and humor all contribute to its uniqueness! That's funny Lucifus, I too saw a scary version of OP originally (I think it was on the Fox network). When I read about it on both these and other anime related forums I tried to avoid it. Finally, I gave in and downloaded the first 50 episodes (I had read that I need to watch up to the Arlong Park arc to fully enjoy it).

Needless to say I watched them and I now am fully hooked on OP and have to wait week to week for the most current release. The Water 7 arc is one of the best story lines that this series has introduced and Oda is truly a storytelling genius! I would and do recommend it to any anime watcher.