Perfect place and perfect host!
I can only recommend Emrah's place: Very clean and very well located: You can reach all the best sites, Aya Sophia, Blue Mosque, Cistern and Suleyman Mosque by foot. Very quiet room and very good bed. You can't imagine that you are in the center of Istanbul! Very good restaurants around. If you arrive at the new airport you have a very convenient bus that connects directly with Sultanhamet square for 18TL. Sultanahmet square is just around the corner. Emrah is a very nice and honnest person. He replied immediately to all my messages. Special thanks to his friend Murat and the ones working at Alla turca gift shop. When I come back to istanbul I will choose Emrah's place again!