From the place's I've tried, starting from the best :

1. Beast
2. Marble 8
3. Hanare ( only on weekend lunch buffet which serves wagyu beef cooked to order...definitely if you're looking to stuff yourself with steak at a "resonable" price ~RM180? including all the other items on the buffet )

Avoid Prime (Le Meridien) and Chambers (Hilton) even with SPG privileges and Hilton Premium Club respectively, both which grant 50% off if 2 people are dining.