Was testing a few expired Promotion Codes on my current order and found these to be still valid even though the original link to the T&Cs on The Good Guys website have been removed, and the codes marked as expired on OzB.
Credit goes to
BeauGiles - APPLE10
https://www.ozbargain.com.au/node/348519
10% off Apple Mac Computers @ The Good Guys
Jimmy007 - CHEF40
https://www.ozbargain.com.au/node/348289
Tefal Chef's Delight 26cm Frypan $17.64 C&C (40% off of Chef's Delight) @ The Good Guys