One exception is a fake love triangle which I often whinge about.

It's when one LI is obviously never going to get MC, but the book pretends there is a triangle going on.
Totally agreed. I hate that. There's no real suspense. Like in Twilight (specifically New Moon). There's no way Bella will ever give up on Edward. So it makes it all the worse that Jacob is throwing himself at her/being
way too nice to her.
At least Hunger Games kept me in suspense about who she'd end up with in the end. I'll give Collins that, as much as I generally detest love triangles.
Why do all love triangles have to be about two boys competing for one girl? I'd like to see a story where the MC is competing for a boy's affection with another girl.
Ashes, Ashes is a book with a situation like that. It's a lesser known YA Post Apocalyptic tale (and frankly, it's not very good). But Arachne makes the point I was going to make about it:
I have an addendum for that: I'd like to see a story where the MC is competeing for the LI's affection with another girl who isn't a stereotypical bitchy cheerleader who couldn't be more The Wrong Choice if she served kitten 'n puppy salad at her sweet sixteen while infecting the guests with voracious alien parasites. In other words, the same thing everyone's saying about the other kind: I'd like the resolution of that kind of triangle to not be so obvious, either.
That's basically what's going on in
Ashes, Ashes except the girl in question isn't a cheerleader, just bitchy. It's very evident that the LI is just in the relationship because he's too weak (or even into himself) to confront her and choose the MC instead. Ugh. I hated it.
On the subject of love triangles (sorry for the derail), what bothers me is relationships being framed in terms of a competition in the first place. When a guy talks about "winning" a girl, I break out in hives, and the whole "Team ----" thing bugs the crap out of me.
So maybe it's just my own fantasy world where there don't have to be winners and losers.
I remember seeing the Hunger Games in theatres and droves of teenage girls wearing "Team Peeta" and "Team Gale" t-shirts. I was peeved because a true fan would've read the books and already known how it resolves. And then what's the point??
Someone needs to write a "Choose your own adventure" love triangle. The author can write both endings and then have their fans war it out over which one gets made "official".
On second thought, that sounds like a terrible idea.