I know why this anime is at the top. A very unique genre. I have watched till ep 261 and am still watching. The show just has no limits and bounds. Never stops to be funnier and more interesting and I haven't even reached the best part as people say. I felt kinda weird watching this anime like around 5 episodes but then I understood how this anime worked and got totally hooked up and fell in love with this anime by the end of around 25 episodes. Just like people say, the story becomes more and more interesting, gets a good plot very slowly but the main thing about this anime is not the plot, but the comedy. I can assure you that this show's comedy is better than any sitcom you might've watched. Also the serious arc is better adapted than any shounen. I just love the shogun assassination arc which is probably the best arc in the anime too. It is amazing how they return to normal after a serious arc.
Overall I would rate this 9.5/10 (Till ep 261).
Now i have watched the whole series and my opinion doesn't change. Legendary show.
just go for it :)