Seitokai Yakuindomo, Oshiete! Galko-chan Recommendations
Both use dirty and sexy humour.
Sex positive, occasionally witty, and dripping with indecency. Both shows consist of a core cast of girls with coarse senses of humour shooting dirty jokes one load after another, hard and fast.
Whilst common anime tropes such the innocent Ojou-sama character is subverted in both series; Seitokai Yakuindomo more or less follows popular manzai comedy traditions whereas Gyaruko-chan relies more heavily on trope subversion, frank realism, and situational comedy.