That's how it begins
Comedy gold, charismatic characters, parodies, hidden plot, drama and laughter. Sket Dance has all of this, used with perfect timing. The story is about a school club that helps other students and even teachers to solve their problems. The SKET dan stands for Support Kindness Encouragement Troubleshoot. Given this summary, at first I thought the anime was about friendship, touching moments and helping other people. Well, it still is about that stuff, and some episodes are about the Sket dan helping people with serious problems, but the main focus is the comedy, and laugh you will.
There are many anime that have characters who steal the show when they appear. Now, imagine when you combine a bunch of these show-stealing characters and put them inside the same school. What you get is something like Sket Dance. Let's start with the main 3 protagonists.
Fujisaki Yusuke, or Bossun, is the leader of the Sket dan. His main "power" is concentrating, as he can gather all information and come up with a solution to most problems. He is one of the most versatile characters ever, as he can be the tsukkomi, the clever one who makes fun of the stupid situation, or the boke, the one who makes the weird situation. He can be a badass by delivering an inspirational speech, or a total child by getting all excited about a car toy.
Onizuka Hime, or Himeko, serves as Sket dan's muscles. She is a ex-delinquent who can be gentle or a hothead depending on circumstances, and Shiraishi Ryoko's kansai dialect portraying Himeko is a total charm! Usui Kazuyoshi, or Switch, completes the team. He speaks through his computer. Normally he's calm and serious, but also like Bossun, he makes jokes all the time and gets easily excited, especially with his otaku hobbies.
All 3 main characters are loveable, and they are not the only ones. All characters in Sket Dance have an "automatic joke", like Saotome Roman's ability to transform everything into a shoujo manga, or Dante's (dubbed by Gackt!) difficult way of speech, or the "modern samurai" Takemitsu Shinzo and many, many others, including the lazy Chuma-sensei and his crazy experiments or Kunio-sensei's weird games. Each of them appear at the right timing to be funny and don't overuse a recycled joke; each appearance is as hilarious as the previous one.
And then, we have the student council. At first, they appear as Sket dan's counterparts, even opponents. But as one would expect, each member is awesome with a unique personality trait. I just love every time Asahina displays her utter and total disrespect with people, sending them to die with her abbreviations!
These guys deserve their own anime
The parodies are constant, be it mocking battle anime, be it exploring clichéd scenes. Even the "otaku world" is portrayed in an awesome way, like when Switch presents absurd mahou shoujo anime like "The Angel of Extortion" or "Maternity Blue". The fourth wall is consistently broken, especially by Roman, and every now and then Sket Dance takes a break to develop the story, characters and relationships with some more serious episodes, especially when it shows the past of the 3 protagonists.
And to top it off, the soundtrack. The show starts off with AKB48's subgroup French Kiss and The Pillows, have a go with Gackt and Evertset, but musically the main attraction is the band who was born with Sket Dance. There is an episode where there is a concert with various bands in school, and Bossun, Himeko and Switch end up forming "The Sketchbook". Well, the band actually exists and performs most of Sket Dance's openings and endings.
There are many factors that make me love an anime, but the main one is charisma. Characters need to feel alive, inspire and be funny, and Sket Dance delivers those generously.