1. Love Bella and Edward's endless love story in the central theme of the "Twilight" series, and while there's a blossoming relationship in "The Hunger Games," it's not the focus. "Twilight" is foremost a romance, and "The Hunger Games" is a hero's journey. Yes, in both books a love triangle develops, and some fans even pick Teams, but Katniss' love life is much more complicated. Katniss isn't even interested in love and marriage; she's too busy trying to stay alive, whereas Bella is completely consumed with Edward and their relationship.
2. Family Katniss is willing to sacrifice her life to save her younger sister, Prim. She hunts to provide food for Prim and their widowed mother. Katniss' love for her sister, the one person who brings her joy, is the sole reason she volunteers for the Hunger Games. Bella, on the other hand, is an only child who at one point is willing to sacrifice her relationship with her father and mother in order to be with Edward forever. She loves her parents, but she doesn't think twice about separating from them to join Edward and his vampire family.
3. Society "The Hunger Games" takes place in a post-apocalyptic future where North America has become Panem, a totalitarian government run by the Capitol, which rules over twelve districts of oppressed citizens. There are major sociopolitical themes in the "The Hunger Games," and Katniss becomes a symbol for everything the Capitol can't control. In "Twilight," Bella's world expands to include the paranormal subculture of vampires, werewolves and shapeshifters, but the obstacles in the story are really set up as a threat to her life with Edward not life in general.
4. Strength Because she has no supernatural powers for most of the story, Bella requires to be rescued a lot. In fact, she's known to be quite ungraceful and needs help from both her vampire and werewolf pals to avoid danger. There's nothing wrong with that -- no one expects a klutzy teenager to outfight a bloodthirsty vampire. But she's no Katniss, who's a skilled hunter and a clever survivalist. Katniss is like a badass Girl Scout who can do everything from fashion a bow and arrow out of sticks to climb the highest up a tree to track a person or animal with the quietest of steps. She's the one who does the rescuing.