I didn't think so either; I watched it up to the Arlong arc (forgot which episodes they were, just know it was before 50) and a couple of weeks ago I read so many people were compait to Naruto & Bleach so I didn't fully comprehend why they were saying that.
So I began to search for OP AMV's and let me tell you that after I watched numerous amounts of them, I was so hooked on it.
So my advice to you is watch AMV's and then you'll see if it is for you or not
P.S. Here's a few I remember of the top of my head:
1. One Piece-This is war(has like over a 1 mill views)
2. This is One Piece(I think it's the most watched one)
3. One Piece-Phenomenon