I hate "The Love Triangle" with a burning passion. Specifically, I hate the triangle which is based around a female protagonist "torn" between to male characters (in reality leading them both on). The most egregious aspect of this trope is that one of the suitors is always a so-called "Bad Boy" who is invariably possessive, controlling and abusive, which inexplicably makes him irresistible to the heroine; whereas, on the other hand, the second suitor is always a so-called "Nice Guy" who is caring, considerate and loyal, yet somehow this means he is a boring loser who is incapable of stirring the heroine's passions. (In other words he is far to good for her.) Three guesses as to which of the two suitors always wins in this scenario.
Before anyone asks; yes, I am a very bitter "Nice Guy" who always lost out to the "Bad Boy" and that may have influenced my feelings towards this particular trope.
Every. YA. Novel. Ever.