School Days: Twilight, except without vampires and more death.
Bakemonogatari: Teen goes around helping other teens fight demons.
Fate/Zero: Bunch of dead guys fight each other for a golden cup.
Fate/Stay Night: More dead guys fight each other; necrophilia.
Akame Ga Kill: Evil king. Group of people try to kill him.
Sword Art Online: Log Horizon v2.
Ore no Imouto: Incest is Wincest.
Himouto Umaru-chan: Lazy little sister is perfect outside of her house. We've all been there.
Tokyo Ghoul: Guy gets dumped by girl and by life.
The Devil is a Part-Timer: God lets the Devil live on Earth. Hmm.
Black Lagoon: Everybody and their mothers have a gun.
And finally, we save the best for last.
High School DxD: A perverted teenager is idolized by a group of females and given sexual attention. The females in this show have no sense of shame whatsoever as multiple of them decide to relentlessly pursue this shit stain of a personality (outside of battle).