Media control and manipulation certainly feature as themes, particularly as correlated with the government's use of same as a form of repression. I am not sure that Suzanne Collins mounts the same intellectually compelling argument against government control as in novels like 1984 but the story is a good read for a YA audience and will certainly have people questioning things like reality/competitive TV (Big Brother, ... Got Talent, the Idol shows) and the cult of celebrity. I liked the parts in District 1 before the Games began about the machinations of stylists and TV hosts. 

   The parallels with ancient Rome are interesting; the 'circus' as diversion for the masses compares with 'the hunger games', the triumphant progress of games victors after the event matches with Rome's triumphs for her generals. And Collins even sprinkles a number of Roman names through district one.

As I was reading the first novel in the triology, I kept thinking about Survivor, Big Brother, and any number of other hugely popular televised series from the last couple of decades. Any number of possible themes might emerge from that comparison: To what extent is entertainment also exploitation? Why do we seem to be so obsessed with the idea of surveillance and the widespread broadcasting of images? What are the connections between power and propoganda? Or the differences between alliances and friendships?

The other two novels in the series really continue to develop the idea that image is everything (or, to use fancier terms, what we call reality is itself a construct,) so I'm going to go with that as a theme that hasn't been stated yet in this discussion. The reader learns that nearly all of the main characters (is Peeta the exception?) is concerned with how their image or someone else's image is coming across and what effect it might have on the general population. (Some details in the books really work well in this theme, such as the recurring use of the language of film editing. The whole "Mockingjay" costume thing in the third novel struck me as a little too much like a comic-book superhero, though, but it certainly also works with this theme.)

There are a few themes that can represent the Hunger Games. The easiest to see is, of course, survival. The tributes fight against each other and the elements to survive the games. And the citizens of the districts fight to survive their daily lives where. In the later books this theme continues.

A further look could focus on human rights and equality of citizens. Citizens of the Capitol have every luxury and do not have to choose tributes to fight in the games. And the districts who normally win the games are rewarded with regular supplies. Other districts, like Katniss's District 12, are constantly faced with shortages. This could be taken farther to explore different types of governments. This as well is further developed later in books. You even compare current events in the Middle East to events in the last book.

One of the most prevalent themes in The Hunger Games is survival, and keeping your humanity and dignity as you try to survive. Katniss and Peeta must survive the games of course, but they also must survive their daily lives in the district. The capitol has made life incredibly difficult for those living in the districts, and to survive the lack of food and adequate necessities requires great strength of spirit. Some people in the districts give up, and others manage to survive but become heartless or mentally unstable. Katniss is a true survivor, she pulls her family through the tough time after her father's death, when otherwise they would not have survived. Katniss' mother is one of the ones who gives up, and becomes mentally unstable when her husband dies. Katniss realizes that she must stay strong and in control in order to keep her family alive. She continues this practice during the Hunger Games. During Katniss and Peeta's training, Peeta tells Katniss that if he dies in the arena, he wants to do it with his dignity intact. Peeta knows that chances of survival are slim, but if he can die as himself, with his humanity and dignity in place, he can face death. In other years of the games, people had gone insane or become incredibly violent and homicidal, eating competitor's hearts and doing unspeakable things in order to survive. Peeta is not willing to compromise his humanity, and would rather die with dignity.