Plain Sight - Out of this world swordfighting/gravity game. Not many people in the servers but the AI is decent enough on normal or hard.
Altitude - neat little dogfighting game. There seem to be heaps of servers and you get decent pings in the Aussie ones.
Runaway: A Road Adventure - Random old-school point 'n click adventure game. It looks beautiful and the plot is actually pretty good. I got it for $2 during one of the sales.