I always backed up before picking up a long-running series, you need to invest a lot of time before the climax, but I don't regret wasting a single minute of watching Gintama.
The story is pretty simple at first, you could just take it as a light-hearted comedy series but there are a few serious arcs that makes you depressed and filled with god-tier character development and growth that you'll feel attached forever.
The best part about Gintama is obviously the characters, Gintoki: a lovable MC that can make you either laugh or cry, his past is easily the best backstory of all the Worldwide fiction series. The other mains are lovable too, all of the Shinsengumi is quirky and eccentric, it won't stop make you laugh whenever they show up
and finally Elizabeth. What can I say? Such a perfect character for Gintama. I still dream about Elizabeth nowadays.
I highly doubt that anyone could not like Gintama's comedy: it's filled with parodies, from WSJ to videogames, you can easily find something to laugh at; for example, do you like Dragon Ball, Bleach and One Piece? Gintama got all of them. Even if you don't get all of the jokes the cast will make it up for you.
Unfortunately Gintama is filled with fillers. Almost every one of them is good, except the first two episodes which are pretty trash and skippable (I recommend skipping it and watching them whenever you like).
The music is awesome, I listen to all of the openings while going to work on my Station Wagon everyday and I'm still astonished that I haven't got into a car accident yet. The endings bang pretty hard too, and most of the OSTs fit perfectly, congrats, sound designers!
The serious arcs, on the other side, are the complete opposite, I'll try to not spoil so I'll keep this paragraph to the minimum: Gintoki as a child probably tops Thorfinn's story easily (Vinland Saga), his duality with Hijikata is top notch and top 1.
My favorite arc is the Kintama arc because it displays that Gintoki isn't perfect, but it's perfect that way and we don't need a perfect one.
Also, Gintama is one of the maximun exponents of the LGBT community, starting a lot of ships between the characters.
Gintama is an unforgettable ride that fills you up with laughs, emotions and by the end you'll feel attached at every character like it was a real friend.
