On other posts, I've been pretty hard about the issue of the so-called "love triangle" in THG. It drives me crazy when the books get reduced down to this. But, there is something about the relationship between Katness, Peeta and Gale that I think reveals another topic of discussion in the books. I don't think the question should be "Who should Katniss have chosen?" I think the better question is "What led her to make the choice she made?"
Often, when reading the books, I found myself wondering how Katniss' life would be different if certain things hadn't happened. What is her father had never died? What if the Hunger Games had never occurred? What is someone other than Peeta had been the boy chosen? What would Katniss be like?
We are all shaped by the events of our lives. Tragic events scar us deeply - changes the course of who we are and what we were meant to be. I think that Katniss spent a lot of time thinking "I could have done this. I should have done that. If I did it again, I would do this." When we get into this Team Peeta/Gale nonsense, I think that it is really a discussion of which Katniss needs to be with which boy. Katniss changes due to the these tragic events - the course of her life is altered.
District 12 Katniss belonged to Gale. He was her best friend. They had so much in common and understood one another. He was coming into his own awareness of her as more than just a friend. They only needed more time to let their feelings evolve. There was no reason to think that they wouldn't get that time.
Hunger Games Katniss eventually belongs to Peeta. He became her life-line. They experienced unspeakable suffering together. They needed each other to hang on to the threads of their humanity. In the end, they depended on each other and their love was deeply imprinted due to their common experience.
I understand the sense of loss that Katniss and Gale didn't end up together. What they could have had was ideal and innocent and sweet. But, the opportunity was missed and they couldn't go back. They weren't the same people anymore. What could have been was gone? Should they have ended up together? Sure, but things happened. Life is not fair.
This is why I don't think that there is a "love triangle" in these books. It's not just about a girl choosing between two guys. It's more than that.