Team Peeta! Gale is an amazing person but he's not right for Katniss, as she says with the whole "I had plenty of fire of my own. What I needed was the dandelion in the spring..." etc, etc. (sorry, I might have misquoted but I've only read Mockingjay once and I don't have my own copy). Plus technically, Peeta knew her before Gale did because he gave her the bread before Katniss and Gale's first encounter. :)
As i read the books i was always Peeta but when i saw the movie Gale seemed to be a bigger part of Katniss's life.
I never saw Gale as a bad person, I just always liked Peeta more. Gale has always struck me as an angry person. I loved the friendship between Katniss and Gale, but the romantic situations never felt right. Peeta loves Katniss for who she is. He sees through al of her flaws, and forgives her for hurting him time and time again. I choose Peeta.