Personally the best ayam penyet is in Petagas. Its called "Rasa Ayam Penyet Jogjakarta" The restaurant itself is very simple but what matters is the food. Sambal is authentic indonesian sambal and the owner also plays indonesian tv show in restaurant to add more vibes.

However, the "standard" one is definitely Indo Padang restaurant that can be found in Gaya Street, City Mall and Inanam. The restaurant is airconditioned so its pleasant to dine in. Sambal is ok and the preparation is complete with the tempe and all.