Just a few suggestions....I'm certainly no expert on Istanbul but over the course of 5 - 6 days I found, tried and liked the following 2 restaurants:

1. Cennet (Sultanhamet, Divanyolu Caddesi 90) Basically on a main touris street in Sultanhamet...but what I liked was that the restaurant makes fresh gozleme (basically pancakes) in front of you. You basically order the pancakes with fillings (or was it toppings)? Either way, I really liked it. I do think it's touristy...avoid the wandering musicians...but the food was good.

2. I don't remember the name but it was kati-corner across from the Blue Mosque. The restaurant is on the top floor of a hotel (Blue house hotel?) and it has a great view of the blue Mosque at night (the dome is all lit up). Again, touristy but the view was grand. When you stand with the Blue Mosque behind you , facing Haghia Sophia, this hotel is on your right. I remember it was blue...Does anyone else who lives or has visited Istatnbul know the name of the hotel/restaurant in #2...