Jokes, jokes, jokes. It usually shows countless references to other anime, such as a pin, a symbol, a name, often and willingly making jokes. Comedy subgenre, often criticized.

Blood Lad

23 min, 10 episodes, 1 season \ parody - demons - vampire - seinen - supernatural - action

Carnival Phantasm

15 min, 12 episodes, 1 season \ parody - comedy - supernatural

Cromartie High School

12 min, 26 episodes, 1 season \ parody - shounen - comedy - school

Excel Saga

24 min, 26 episodes, 1 season \ parody - comedy - sci-fi - shounen

FLCL

25 min, 18 episodes, 3 seasons \ parody - psychological - mecha - comedy - sci-fi - dementia - action

Genshiken

25 min, 37 episodes, 3 seasons \ parody - comedy - slice of life

Gintama

25 min, 367 episodes, 10 seasons \ parody - action - comedy - historical - samurai - shounen - sci-fi

Hagane Orchestra

5 min, 12 episodes, 1 season \ shoujo-ai - game - parody - adventure - comedy

Hayate the Combat Butler

25 min, 101 episodes, 4 seasons \ parody - action - harem - comedy - romance - shounen

Hetalia Axis Powers

5 min, 140 episodes, 4 seasons \ parody - historical - comedy 

Isekai Quartet

15 min, 24 episodes, 2 seasons \ parody - fantasy - comedy

KonoSuba: God's Blessing on this Wonderful World!

25 min, 20 episodes, 2 seasons \ isekai - magic - supernatural - fantasy - parody - adventure - comedy - game

Lucky Star

25 min, 24 episodes, 1 season \ parody - slice of life - comedy - school

Maria Holic

25 min, 24 episodes, 2 seasons \ yuri - comedy - parody - school - shoujo-ai

Martian Successor Nadesico

23 min, 26 episodes, 1 season \ mecha - action - comedy - military - parody - romance - sci-fi - shounen - space

Monthly Girls' Nozaki-kun

25 min, 12 episodes, 1 season \ parody - comedy - romance - school

My Bride is a Mermaid

25 min, 26 episodes, 1 season \ parody - comedy - shounen - school - romance

No-Rin

25 min, 12 episodes, 1 season \ parody - comedy - ecchi - school - romance

Nyaruko: Crawling With Love!

25 min, 24 episodes, 2 seasons \ parody - sci-fi - comedy

One Punch Man

25 min, 24 episodes, 2 seasons \ parody - action - sci-fi - supernatural - super power - supernatural

Osomatsu-san

25 min, 75 episodes, 3 seasons \ parody - comedy

Ouran High School Host Club

24 min, 26 episodes, 1 season \ reverse harem - parody - shoujo - comedy - romance - school

Outbreak Company

25 min, 12 episodes, 1 season \ isekai - parody - fantasy - harem - comedy

Samurai Flamenco

25 min, 22 episodes, 1 season \ parody - comedy - action - super power

Sayonara, Zetsubou-Sensei

25 min, 38 episodes, 3 seasons \ parody - comedy - shounen - school

School Rumble

25 min, 52 episodes, 2 seasons \ parody - comedy - school - romance - shounen

Senyuu

5 min, 26 episodes, 2 seasons \ parody - action - comedy - fantasy - shounen

SKET Dance

25 min, 77 episodes, 2 seasons \ parody - school - shounen - comedy

The Disastrous Life of Saiki K.

24 min, 48 episodes, 2 seasons \ parody - school - shounen - slice of life - supernatural - super power

The Irresponsible Captain Tylor

24 min, 26 episodes, 1 season \ space - parody - military - comedy - sci-fi

The Melancholy of Haruhi Suzumiya

25 min, 14 episodes, 1 season \ parody - comedy - mystery - slice of life - sci-fi - school