I can only recommend this place. Aylin was very welcoming and even left some food and drinks in the fridge so I could have breakfast on my first day. The apartment is big and very well located. Taksim square is only a few minutes away.
Also, Aylin runs a nice little vegetarian restaurant just opposite and is always there in case questions come up. She even gives you a discount on meals. So, don't miss the restaurant when you stay in her apartment.