Battle Royale.

http://video.google.com/videoplay?docid=4036233620196000189&q=battles+royale&total=6563&start=0&num=10&so=0&type=search&plindex=1

I bought halo 3 for only one reason. To play its campaign mode. Don't get me wrong the campaign mode is great, but the online is over rated. About 40% of the people who have owned halo 2 will tell you that it was over rated. I think that It was because Microsoft advertised it a bit to much also because Microsoft owns and regulates Xbox and Xbox live.