I love, love, LOVE Leb-i-derya. I don't care one jot that it's over-priced. It's refreshing to find a society in Istanbul hangout that's friendly and welcoming - even on a Saturday night in July without a booking. And the views are sublime. Try to arrive before sunset otherwise you'll completely miss the point and good luck in finding it! If you get lost, ask the doorman at the Richmond Hotel on Istiklal Caddesi for directions...
Kumbaracı yokuşu 57/6 Tünel, Beyoğlu
www.lebiderya.com/