The worst kind of DLC is stuff that should be in the game, but isn't. The best DLC adds to the game experience.
Square Enix is currently churning over the idea of including DLC for upcoming role-playing-game Final Fantasy XIII. Says FFXIII producer Yoshinori Kitase, "Our plans for [Xbox Live and PlayStation Network] are currently unclear."
"We are exploring the option of downloadable content, perhaps adding new areas, items or enemies," the producer added, "but these would not be expansions to the story, only the gameplay. The entire story of FFXIII will be on the disc." As it should be!