A lot of my pet peeves define almost the entire rap genre.
- Constantly referencing yourself in your music.
- Writing songs about yourself. I don't care if you're in the house.
- Writing songs about how rich you are.
- Writing almost every song in the first person.
- Yelling out random cliches that have nothing to do with the song ("where my ____ at?," "make some noise," etc).
- Bashing other artists.
- Excessive use of curse words.
- Mispronunciation of words, and grammar that isn't even close.
- Inconsistent theme from one verse to the next, or complete lack thereof.
Here are my metal pet peeves.
- Untrained vocalists (especially for clean vocals)
- Female fronted bands and all female bands that boast of their high female participation, but aside from their parts, have nothing else to offer.
- Solos that are essentially a string of random notes and don't fit the song.
- Orchestral sections or synths for their own sake.
- Breakdowns that don't fit.
- Corn snakes and ball pythons are not cobras. In fact, just don't pose with any other species unless it's relevant to the theme of the song / album.
- Using the same key, scale, progression, tempo, beat, and / or time signature in virtually every song.
- Playing tremolos for an entire album.
I'm sure I'll think of more later.
EDIT:
- Excessive tremolos and blastbeats
- Dissonance for the sake of dissonance.
- Poor quality / production for the sake of tr00ness.
- Anything for the sake of tr00ness.
EDIT2: I agree with the comments about the hidden tracks and drifting toward metalcore. As for hidden tracks, I don't mind when there's a track that doesn't appear in the listing, but I hate it when there are two songs on one track, seperated by like two minutes of silence. With regard to metalcore, I don't have anything against metalcore, or even nu-metal since I still like some of it. However, while metalcore is more radio friendly and easier to write, I think that if you've already established a certain sound with your band and you want to change it that much, you might as well just start a new band so that you don't completely discredit yourself in the eyes of your original fan base.