I finished off Halo 3 last night and it is definitely THE best game I have ever played (note I am a big fan of the Halo franchise).  I took some gameplay footage below of my battle with the Covenant Scarab, have a look at the graphics: 

Xbox Australia has also launched Red vs Blue which is a charity initiative where you can bid for Xbox 360 consoles which have been signed by celebrities such as Justin Timberlake, Kanye West, 50 Cent, Pussycat Dolls to name a few.  You can either support the Red Charity (Mission Australia) or the Blue Charity (Make A Wish foundation).  Bidding starts October 2nd.