What's funny is it's not even adaptation decay. The game it's based on shares nothing in common with it but the title. So their original plot involves spending almost an entire show making one of the choices interesting, and then defaulting to the first one as soon as the main character discovers it's not incest if he does so.
You say no Noe route? This game must suck.
As people before mentioned, I dislike when male character crashes with a female character and it takes them a lot too long to get away from each other, also, face on her skirt/boobs/hands on boobs. Any normal human being would put their hands on the ground just because a guy falling on a girl could easily hurt her, and her soft body is not exactly a good place to support his hands. Then, even if they end up in a suggestive position, it doesn't take so much time to stand up and apologise. What is more, it isn't really hard to think of a situation when guy could accidentally grope girl's boobs without breaking the laws of logic.
I am annoyed by series with endings so open, that it's like nothing even happened(comedies may not apply to this rule).
Huge boobs and spending several minutes of each episode on showing them.
Those and more are so common because it's and easy way to make somehow popular anime without thinking of anything original.
Oh, and when there's a great solution used in ep x that would be perfect for a situation in ep x+n, but they somehow forget it and make a whole episode about doing it the other way.
Pussy main character that has super powers but hesitates to use it causing damage(or deaths) again and again is also so freaking annoying. I was really thankful that in Gundam(Seed? I'm not sure) the main character after a while has decided to leave doubts out of the battlefield.
Overreacting to some things that also causes an episode of pain, I feel a terrible lack of reason in more than half of animes I watch.
Hope it's understandable because I struggled to put some of those sentences into english.