To be honest, when my brother told me about this manga i was a little skeptical on the grounds that it sounded a lot like another SJ title known as Gintama. That (to this day) is true. In fact the main cast is composed of three leads as well. But there's a reason as to why the two series's share similarities, Kenta Shinohara(the author) oppenly stated that used to work as an assistant under Hideaki Sorachi (the author of Gintama). So it's natural for the influence to be there and ,to be honest, aside from the plot (Three leads do all sorts of nonsensical jobs) Sket Dance is a manga that stands gloriously on it's own and is by no means a ripoff.

Moving onto the story, Sket Dance has no all consuming story with a beginning and an end, rather it's composed of episodes. Each chapter chronicles a new case for the Sket Dan and occasionally certain arcs (which can span up to 3-6 chapters) like the: "Sket Dan vs. The student council" arc. The cases are most of the time nonsensical and random: Like the chapters in where they have to deal with the Roman, the girl who sees everything in her 'otome filter' (in short Shojou manga vision). However they may equally be touching and at times sad and very deep. The most touching arcs in my opinions are the ones that explore the pasts of the three leads and how they came to join the Sket Dan. For spoiler reasons i wont explicit on the content of these chapters. Just know that you are guaranteed to at least get teary-eyed at one them.
The story mixes ridiculously funny humor with ,at the same time, drama and suspense worthy of a shojou manga.

Now the characters, the one thing i can say about the cast of Sket Dance is that it's unique and very colorful. The three leads are: Fujisake Yusuke otherwise known as "Bossun" (the protagonist), Kazuyoshi Usui or "Switch", And Onizuka Hime a.k.a "Himeko". Obviously these three characters receive the most development of the cast. Bossun acts rather childish and hot-blooded and in one chapter is even made out to be a "useless shonen hero" by an amateur manga artist. However it's thanks to his talents that the Sket Dan is able to solve many cases. In a way you could describe him as being a sort detective because he is able to analyze, and logically solve most dilemmas that come his way. Then we have Himeko the "straight-man", who ironically used to be a Yankee so feared that she was nicknamed "Onihime" a name which she she, nowadays, rejects. And finally Switch, the apparently good-looking otaku who uses a voice synthesizing software on his laptop to speak.He is stone faced but often willingly gets involved with the nonsensical situations of the show.
The supporting cast equally receives varied levels of development. The most notable being Tsubaki, the student council vice president and possibly Shinzo the phony Samurai.

Sket Dance's art is generally varied in terms of quality. It ranges from a little below average to holy-shit-that's-freaking-godly.To be fair, It was sometimes impossible for me to appreciate the art for the sole reason that the scans were messily cleaned up and they looked rather poor in quality. But the most notable instance of absolutely mind blowing art is arc which explained Bossun's past. I honestly dumbfounded at the level of detail and expression revealed during those chapters. It's clear that Shinohara can draw very well both with comedy and in drama.You really connect with the characters regardless of who they may be. Not to mention certain expressions can just make you laugh so hard.

Overall Sket Dance is an extremely good and cleverly written manga,definitely one of my favorites . I enjoy it very much, most notably ,of course, because of it's comedy but also because of the characters and it's ability to have "a different and truly unique approach to the same idea".
There are no overly negative aspects to the manga. However some may argue that the humor can get a little repetitive, i personally love it.
It's a shame that on the international circuit it doesn't have much a fan base because it truly is one of my favorite SJ titles alongside Gintama and One Piece.I'm confident that it will stay in publication and i sincerely hope it gets an anime adaptation. It is already slated to have a drama CD after all!