Either Peeta or Foxface, I think you were supposed to like Foxface. I've always thought her death was just thought up of to get rid of her, the way she dies shows she wasn't ever a main character. It was the same with Thresh we were supposed to like him, respect him, but it was always obvious he wouldn't win. So just like Foxface he was killed off.
If I really had to pick a favourite between these two it would be Peeta, because he gives Katniss the bread, always tries to protect her. The worst bit of the whole trilogy is the bit where Peeta tries to strangle Katniss. It made me read on to see if it all worked out, if he ended up with Katniss.