Book through Dimmi's special 50% off food bill offer to get 50% off your bill (food only, you must pay full price for drinks). These guys make good steaks. They are expensive but that's what the 50% off is for :-)
Bookings seem to be only available on Mondays, Tuesdays and Wednesdays at 6.30pm or 8.30pm. This deal is for Kingsleys near King and Kent Streets and not the one at Woolloomooloo.
There's also another 50% off Dimmi special for Grafitti Ristorante at Arthouse Hotel. Link to that deal is here: http://www.dimmi.com.au/restaurant/kingsleys-australian-stea...