Wacky Homeroom

Often, when a show centers around a particular class, the teacher and the students have distinctly quirky personalities. Sometimes the focus of the series is more on the teacher, and sometimes it's more on the student; one way or another, though, people in Real Life can only wish their classes were this colorful. Or not. It depends.

Anime and Manga

 * Gap
 * Azumanga Daioh
 * Cromartie High School
 * Gokusen
 * Great Teacher Onizuka
 * Hidamari Sketch
 * Mahou Sensei Negima. "Wacky" in this case means Badass and/or Crazy Awesome.
 * Pani Poni Dash!
 * Sayonara, Zetsubou-sensei. SHAFT (who animated Pani Poni Dash! and Negima Second Season as well) seem to do this trope a lot.
 * Notable in that it has a psychotic group of dysfunctional students, headed by a suicidal teacher, all played for very dark laughs.
 * Sketchbook. Okay, it's an art club, but the effect is pretty much the same.
 * Doki Doki School Hours
 * Ichigo's homeroom in Bleach could certainly be described as wacky. Outside of the fact that the teacher regularly mocks the students, the room has been invaded by shinigami multiple times, and one time Kon showed up in Ichigo's body. In all cases the room was essentially destroyed. Oh, and the teacher doesn't even seem to care about Ichigo and his friends either not turning up for class or running out in the middle of it.
 * Potemayo
 * The TV-series of All Purpose Cultural Cat Girl Nuku Nuku introduced a class of walking cliches for Nuku-Nuku to interact with. They're even introduced with an appropriate tag such as 'Snobby Rich Girl' or 'Nihilistic Pretty-Boy' whenever they appear on stage. This was noticeably absent from the OVA, where Nuku-Nuku went to school once, prompting the destruction of most of the premises in a fight between her and an attack helicopter. They didn't try to send her to school again.
 * Hyakko
 * Minami-ke is becoming like this in later episodes, with its bigger emphasis on the three sisters' classmates.
 * Lucky Star, at times.
 * Rosario + Vampire has shades of this, especially in season 2, when the entire Unwanted Harem ends up in the same class together. And then there's their teacher.
 * Mitsudomoe
 * The cast of Soul Eater probably qualify. Not to mention their homeroom teacher is a Mad Scientist.
 * A Certain Magical Index, although the entire series isn't exactly focused on the protagonist's homeroom.
 * School Rumble. Oddly fitting with its name.
 * Nichijou: Emphasis on the wacky.
 * Misaki Number One
 * Maicchingu Machiko Sensei had a very colorful homeroom and the quirkiness branched off into other teachers and members of the faculty as well.

Comic Books

 * In The Beano, the Bash Street Kids all had distinct personalities. Of course, there were only 9 of them.
 * The Peanuts fit this trope when they have scenes in school.

Literature

 * Hogwarts is all about this.
 * The Wayside School series, originally a set of books by Louis Sachar and since animated.
 * Susan Sto Helit is a proper young woman, who is entirely sober and rational and will not stand for even the usual amounts of silliness that a child usually displays. Her class is extremely well-behaved and sensible. She just happens to take them on literal trips through time and space without ever leaving the classroom. Because she's Death's granddaughter. But she keeps her past so quiet that her employer is surprised even to find out that she is a Duchess.
 * Having said that, a few students do have personalities that push them into Wacky Homeroom territory: Vincent the overachiever, Penelope the Brainless Beauty, and Jason the Enfant Terrible.
 * Boy Meets Boy by David Levithan takes place in a high school that, among other things, have cheerleaders who do their routines on motorcycles.
 * During the late eighties, Scholastic had a YA book series called Homeroom. As it was Exactly What It Says on the Tin, it followed the misadventures of an 8th grade homeroom. It had all the stock YA characters: the Alpha Bitch, Jerk Jock, Cool Loser, The Cheerleader, etc.

Live Action TV

 * Head of the Class
 * Welcome Back, Kotter
 * Seven Periods With Mr Gormsby
 * Brazilian show "Escolinha do Professor Raimundo" (and its more recent copycats) is (and are) centered around one such homeroom(s).
 * Misaki Number One
 * Saved by the Bell focused on one set of students and no main teachers, but they somehow always shared the same classes, subverting this trope. The first season however, played it completely straight since it was originally called Good Morning Miss Bliss and took place mostly inside one classroom.

Video Games

 * Disgaea 3
 * Persona3

Web Comics

 * Largo's class in Megatokyo. Not only is it taught by resident Crazy Awesome Cloudcuckoolander Largo, but some of it's more colorful members include a Robot Girl, an enigmatic Elegant Gothic Lolita who may very well be a Dark Magical Girl, and a class representative who practices Enjo Kosai and has an alcoholic dad. Also, the class's first field trip involved them taking on a horde of fanboys/zombies.

Western Animation

 * The Magic School Bus series. Ms. Frizzle is decidedly wacky, and her class, while not as quirky as some other examples, are unique in their own ways.
 * Recess
 * Bubble Guppies