Graphic Resources / Sounds / Musics / Programming

SpriteLib
"SpriteLib GPL is a collection of hundreds of free high quality, animated images that are ready to be plugged into your game creations. Supporting several different game themes, you'll find SpriteLib GPL an indispensible resource. "

MameWorld
Many classical game sprites

molotov.nu
Excellent sprites and tiles of some games

GSA Game Sprite Archives
Search sprites in a categorized list by system and game