Dead Rising - 7.3 GB
Tomb Raider Legend 7.2 GB
N3 - 7.2 GB
GRAW - 7.0 GB
Dynasty Warriors 5 - 7.0 GB
Test Drive - 7.0 GB
Battlefield 2 - 7.0 GB
Top Spin 2 - 6.5 GB
Burnout Revenge 6.6 GB
Condemned 6.7 GB
Oblivion - 6.5 GB <------half of the space is taken up by voices
Far Cry - 6.5 GB
Bomberman 6.7 GB
King Kong 6.1 GB
Dead or Alive 4 - 4.7 GB
Table Tennis - 1.9 GB
EveryParty - 600 MB
NHL 2K7 - 4.2 GB
Amped 3 - 6.7 GB
Blazing Angels - 5.9 GB
Call of Duty 2 - 6.7 GB
Chromehounds 5.7 GB
Enchant Arms - 6.7 GB
Fight Night 3 - 6.3 GB
Full Auto - 5.9 GB
Gun - 7 GB
Hitman - 6 GB
Just Cause - 6.1 GB
Kameo - 6.3 GB
Lego Star Wars - 5.9 GB
LOTR Middle Earth II - 6.6 GB
Madden 2007 - 6.6 GB
MotoGP 2006 - 4.4 GB
NCAA Football - 6.7 GB
NFS: Most Wanted - 5.5 GB
NHL 2007 - 6.1 GB
OverG fighters - 6.7 GB
PDZ - 6.2 GB
Prey - 4.6 GB
Quake 4 - 4.7 GB
Ridge Racer 6 - 5.1 GB
Rumble Roses 5.2 GB
Saints Row - 5.9 GB
Tiger Woods 2006 - 7.1 GB
Tony Hawk AW - 6.6 GB

Some dev hasn' t compressed their files as they can,thus some games goes up high.
Or put in some crappy CGI.