Well look at the Crackdown demo, rising up the charts. Is it a sign that people like the game? Or are they just trying to justify their purchase of it for Halo 3's beta. 

360:

• Gears of War
• Crackdown (demo)
• Tom Clancy's Rainbow Six® Vegas
• Call Of Duty 3
• Lost Planet

Live Arcade:

• Heavy Weapon
• Hexic HD
• UNO
• Lumines Live
• Geometry Wars Evolved

Original Xbox:

• Halo 2
• Battlefield 2: MC
• Madden NFL 07
• Counter-Strike
• Call of Duty 3

[Source: Major Nelson]