I have a 60GB drive in mine and can have about 2 full retail games and about 6-8 smaller psn games on there. Maybe you have some stuff in the game and save data folders taking up a load of space? I haven't been a heavy PS3 user so I don't have that much in there plus I deleted most of the stuff from games I won't replay anyway.
Please don't use the delete button, think of the children.
