I'm surprised that there isn't any thread for this anime yet. Gintama is, by far, the funniest anime I've ever seen in my life. Why do I think so? Well, it's relatively easy to create a 25 to 40 episode comedy anime series without any difficulty at all. However, to create a comedy anime series which extends over 200 episodes and is still ongoing, and seems to make you laugh (or move) in almost each and every episode - that kind of anime is difficult to make. That is Gintama.
Other than that, I'd say that the main character, Sakata Gintoki, is the reason why I just love this show (there are others like Kagura too, but he's the real deal). If I'd have to pick the Best Anime Character out of all animes, it would definitely be him.
Anyway, use this as the regular discussion thread.