Note: this post involves sarcasm.
1) Brooding vs Optimistic
This is the type I see most often in YA. The heroine will meet two guys at the same time who are completely different from each other. One is probably blonde, with a charming grin, and eyes like the sea. He's bright, bubbly, and falls madly in love with the heroine.
The other is most likely dark haired, who says little and is so mysterious the heroine is drawn to him. Dark-Haired is a rebel with a cause, and loves the heroine, but is afraid to say it. Oh, and they're both devastatingly attractive and make butterflies flutter around in her stomach.
But she chooses the latter because every heroine is drawn to the tragically misunderstood rebel.
2) Perfect vs Perfect
The two guys are both extremely muscular, make all the girls sigh as they walk past, and seem to have no flaws except maybe a past they can't control. The heroine is, of course, equally in love with both of them, and just can't choose!
But don't worry, one of them will probably betray her trust, so she'll won't have any problems choosing anymore!
3) New vs Past
In this love triangle, the heroine is torn between an old friend she's grown up with and a dashing young man she's just met. Should she go with the guy she knows well, or throw all caution to the wind and be swept up by the new one?
Bonus: Love Square/Pentagon/Decagon
This heroine can never seem to find the right guy, and every man she sets her sights on loves her within hours. It seems by the end of each book her current guy betrays her, she doesn't like him anymore, and then finds someone else. Of course, since her exes never seem to get over her, it can make things a little more complicated...
I'm curious; do you enjoy love triangles if they're done right, or do you steer clear of them completely? Which of the above love triangles do you see a lot? Any types that I missed?