This time last year, I was up to date with Bleach & Naruto and I decided to give One Piece a go. When One Piece was first broadcasted on Cartoon Network, I thought it was childish and crap as it was about pirates.
However, in Jan 2011 I've stuck at it and decided to watch ep1-current. Yes it's childish from the start but the CP9 arc is where everyone matures, and all the characters become serious. The little childish jokes in some episodes during and after the CP9 become quite funny... You need that because the Bleach & Naruto storylines has become depressing