If you're looking for a 5 star hotel with room service and all that, skip.
If you're planning a very comfortable visit to Istanbul, staying in the middle of the old city where you can reach the most important sites with a short walk while maintaining a low budget, read on.
The Sirin Gold Hotel is a place where you'll feel homey at arrival. I did. From checkin to checkout after 2 weeks, I was treated not only as a valuable customer, but as a very welcomed guest. I got a free-of-charge room update after the first night without asking for anything, and sincere apologies for I had to stay in the tiny room I had booked coz a better room wasn't avail that day.
Most of their staff speak English kinda fluently, and if you're (even in the middle of the night) are faced with someone who doesn't, you're invited to free tea or coffee at the bar. It usually takes less than 5 minutes to get you a guy who not only perfectly understands you, but also is able to fix your problem in no time, regardless whether you're asking for tour guidance, airport transfer, help with getting or recharging an Istanbul Kart (public transportation), additional pillows, or whatever.