shit! i recommend gears of war on Xbox Live. It's amazing.
Some other games I recommend:
-Call of duty 3 (not that i've played it
)
-F.E.A.R. (if you havent played on PC)
-Splinter Cell: Double Agent (if you plan on getting xbox live. the single player is awwwesome! but the multiplayer is the best)
-Viva Pinata (it looks like its for kids, but I guarantee that if you play it for 1 hour, youll be hooked. one of the deepest games out there AND the most fun).
-Condemned: Criminal Origins - a launch title, but still plays fantasticly. Probably the scariest game ever. You can get the demo on live, too.
Also, if youre interested, I can PM you the link to a site off which you can get 360 games for around $60 including postage! It's based in Asia, and quite a few titles (such as the ones above, apart from viva pinata) are region-free, meaning you can play them on your aussie console. I've saved soooo much