Doubtless this has been discussed amongst your geek herd already, but if you haven't heard, claims are being made that Hunger Games author Suzanne Collins lifted a bunch of plot from a Japanese novel called Battle Royale by Koushun Takami.
Without spoiling anything from either side, you can know that both stories involve youths fighting for survival against a government who wishes to punish them.
That being said...watching both trailers will clue you in on some of the differences pretty quickly.
So Battle Royale was released 9 years before The Hunger Games. Can the BR fans really say the idea of youths killing or the thought of an oppressive government broadcasting tyrannical horrors is a new concept?
Even if you don't include real historical events like Gladiator battles in Rome, public executions in soccer stadiums in the Middle East, or works like The Most Dangerous Game or Theseus and The Minotaur, we still live in a world where watching movies like A Clockwork Orange and an episode of The Jersey Shore will undoubtedly give someone the idea "HEY I SHOULD MESH THOSE TOGETHER!" Before you know it, you have milk drinking Italian-Americans fist pumping to classical music in the midst of a dark and twisted "situation."
I guess the point I'm trying to make is that it doesn't matter truly if THG stole content from BR because their stories are unique enough and the concept has been done literally and literature-ly since ancient times. If you like Quentin Tarrantino's opinion and excessive amounts of gore go see Battle Royale, and if you have a hankering for better production quality and presentation wait for The Hunger Games.
Oh...and before you flood the comments, I found absolutely no evidence that Battle Royale was ever banned in the United States, hence my not mentioning it.