When I first watched Gintama, I had no idea how hilarious it would be. But, as I watched more of the series and read more of the manga, I found myself laughing very hard at various scenes/episodes/chapters, such as the Bentendo Owee Arc, the Neo Jet Armstrong Cyclone Jet Armstrong Cannon episode, and Otsu-chan's "Chome Chome" (a.k.a. "You Father/Mother/Brother/Whatever is a -xx-"). Plus, there are many things about the anime that I find relateable to my own life:
1. Like Gintoki, Shinpachi, and the rest of the Gintama crew, I live in a big city (Los Angeles instead of Edo), which leads to many adventures in town and the surrounding area.
2. Just like how Gintoki has a crush on the weatherwoman, I know at least one person who has a crush on the weatherwoman.
3. I'm kind of a slacker, I love sweets, and I love anime and manga from Shonen Jump, especially One Piece. In essence, i'm pretty much like a gender-flipped version of Gintoki.
4. The people around me are pretty crazy, just like the cast of Gintama. ^__^
If you are looking for a good laugh, watch an episode of Gintama. Your laughter may range from a giggle here or there to the point where you're laughing so hard, you can't breathe.