I hate 'em. Usually.
Let's define a love triangle as a situation where a girl has romantic feelings for two guys and each of them reciprocates (or visa-versa, but I'll stick with these genders for further examples). This isn't an uncommon situation (but it's way less common than reading YA would have you believe), and I don't inherently dislike this situation.
Where it becomes grating is when the girl tries to 'choose' between the guys like choosing between two flavours of cake, like there's some immediate need to decide on one to be with forever and like two people can actually be compared.
But more than that, the love triangles set up in much YA (I'm trying not to generalise - there are a few love triangles that I actually like!) have the character defining themselves based on their choice, rather than discovering who they are and then choosing. Especially where something happens to one of the girl's options and she assumes she must be with the remaining one. Too few characters in YA triangles really know themselves and what they want before they decide, and that doesn't bode well realistically for the 4eva luv* they plan on having.
For those reasons, I am ordinarily hesitant and/or rubbed the wrong way by love triangles.
What do you guys think about love triangles? Got any examples of ones you like and dislike?
* I'm not a romantic. Can you tell?