There are a ton of futuristic bloodsport movies out there, but Hunger Games is more than just a movie about a bloodsport. It's also a pretty probing political commentary that uses science fiction as a way to critique aspects of our world. The fact that the Tributes who fight in the Hunger Games are between the ages of 12 and 18 may arisen from author Suzanne Collins' desire to hit a young adult market, but in the movie there's a sense of generational conflict going on.
The greatest generational conflict science fiction movie is, of course, Logan's Run. A whole movie based on the hippie mantra 'Don't trust anyone over 30,' Logan's Run is set in a world where you die when you turn 30. Not everybody happily gives themselves over, though, and these Runners are hunted down and terminated by Sandmen. Logan's a Sandman, but when he discovers a society outside of the domed city in which he lives, he too becomes a Runner.
There's a huge sense of silliness in the design of Logan's Run, and that's part of what I love about it. Also, Michael York is an incredible lead and Jenny Agutter is an eternal crush of scifi nerds everywhere. Logan's Run is the kind of movie that people sometimes refer to as 'dated,' but that's such a huge piece of what makes the film magical. It's totally of its time. There's no shame in that.