I received an email offering free sound effects from a UK games developer. I did a little more digging, and found they also offered a graphics table reference for those interested in developing retro-inspired games. Have a look if you're into making retro games, from the Atari ST to NeoGeo. This may be useful. Available via a CC0 license, no attribution required (but it would be nice, eh?).

http://www.themotionmonkey.co.uk/free-resources/