We spent 6 days in Istabul last year - I used Rick's guide, which was really helpful. We had a local friend of ours take us around (guide not necessary) and he was impressed with the amount of detail and information Rick provides. In 5 days you could see a lot if you organize your time and get a map. Using RS guide book and after watching his Istanbul video, I had fun mapping out places I wanted to see. Many sights are close together. Some of my favorites that come to mind (these were full days): Hagia Sophia & Blue Mosque, underground cistern, Sultanahmet area for lunch/shopping (1day). Spice Market & Bosphorous cruise (1 day). Topkapi Palace & Grand Bazaar (1 day). Walk across Galata Bridge, over Golden Horn, Galata Tower for views, if you wish, and on to Taksim/New District (1 day). Suleymaniye Mosque & grounds (mosque closed for repairs last year, reopened now I believe); maybe visit a haman; Archeology Museum (1 day). Visit Chora Church (stunning Byzantine mosaics), walk along Constantinople's ancient city walls; walk through colorful Fener neighborhood (1 day). Etc., etc. .... We did some more stuff around town, too many things to type here, but we had lots of cool experiences like getting balik ekmek (delicious fish sandwiches @ Eminonu), bargaining @ the markets, and so on. One thing I would point out is to check the days in which the different museums are open and hours of operation when planning.