If you dont want to stay in a tourist ghetto then stay clear of sultanahmet and go for the hote#351;s in the Taksim/Besiktas area or anywhere along the Bogaz hatti.
great views from intercontinental and swiss and also the marmara.
Places to see:
Apart from the obvious Aya sofiya, sultanahmet mosque, topkapi palace & kapali carsi I would go for the dolmabahce palace, istikal cad, get the boat to buyuk ada.
restaurants, go for anyone of the many fish restaurants along the boz but I would recommend the ones in Bebek.
Shopping, go for the cevahir mall in Sisli, the largest mall in europe or the Kanyon in Levent which is more up market but a fantastic mall considering the architecture.