I have never seen anyone talk about this series on this forums, so I feel a bit depressed.
If you haven't seen this series yet, you must go see it. Currently, it has 311 episodes and the current arc is really awesome. You definitely wouldn't want to miss out on the greatness hype train.
What genre is this series?
Gintama is everything lol. It has music, sci-fi, mechs, parodies, fantasy, shojo, shonen, etc. Pretty much everything.
But guess what? it works. The series is so good, everything just works. All the serious arc are god-like. The parodies are funny, and the sad arcs are tear-jerking. Seriously, this series can make you cry for a vending-machine. It deserves everyone's attention.
Here's a cool little parody. There's more, but this is just one of them.