In terms of location, the best is Karaköy: It is from there that you can take the ferry to Kadiköy and it is equal distance between the nightlife and the tourist attractions. I recommend you one of the following girl-friendly hotels there (click on the link to check the rates):
Upscale
The main issue with Karaköy is that it is a hipster district so if you don't feel comfortable with it, you may go around Asmali Mecet street in Galata. There is a funicular line from Tünel to Karaköy so it is still an excellent location. The view is also nicer.
Upscale
Mid-range
Pera Tulip Hotel
All these hotels are girl-friendly and near the nightlife. To avoid any issue, it is recommended to mention 2 guests at the time of the booking.
All these hotels are girl-friendly and near the nightlife. To avoid any issue, it is recommended to mention 2 guests at the time of the booking.
