Halo 3

The epic story from Bungie continues with the 3rd installment of the crazy Halo franchise, and it's set to begin September 25th. - just in time for the school year. Some improvements include certain graphical, technical and gameplay advancements, as well as a 'whole new level of online gameplay'. I know, that's pretty vague. Luckily I found a whole slew of video clips here. It will be certain that you'll spend the next 8-12 months glued to this thing, at least I will be. Oh, well. As if I had a life anyway.
-Oh ya, and don't go for this helmet package deal, you can't wear it and it sucks.