Hmm, I hate many brazilian styles and bands that you probably never heard about, fortunately lol.
1 - Samba, Pagode bands - can't remember exactly their names, maybe Exaltasamba, Só Pra Contrariar etc.
2 - Axé music, Sertanejo(brazilian country music) - horrible rhythms such as Axé blonde, Leandro e Leonardo, Sandy e Júnior, etc
3 - Rap, Hip Hop - both national and international artists, I wish I could kill those guys from 'Bonde do Tigrão'.
4 - Pop/Dance/Boy bands/girl bands - things like Britney Spears, Spice Grils, Beyonce make me puke
5 - Power Metal, Punk pop - they are really boring, too happy and ridiculous
6 - All Nu-metal, emocore, and some metalcore bands also sound too boring.
7 - Finnish "goth" bands(and all those bands that promote themselves and get fans just because they are finnish), Lacuna Coil, Evanescense, Avril Lavigne
8 - Within Temptation
9 - Nightwish nowadays
10 - Hard rock/glam in general - Motley Crue, Poison, etc