Cibalikapı Balıkçısı

Cibalikapı Balıkçısı has the reputation of being one of the best seafood restaurants in Istanbul, and in my experience certainly deserves it.

It's a traditional Turkish seafood restaurant, with meze, very fresh fish, and rakı (although there is also a wine menu).  The assortment of different meze dishes was impressive; the meze themselves were good but not spectacular.  Must-haves, however, are the grilled octopus (served almost whole, and far and away the best I've ever had), and the house specialty dessert, a delicious sesame-paste-based concoction that will have you on a massive sugar rush after only a few spoonfuls.  The fried calamari (like the octopus, served almost whole) was also very good.

The decor is a very little bit tacky (with fish nets hanging from the ceiling) but the fabulous views across the Golden Horn toward Galata more than compensate, and the traditional Turkish music playing in the background lends an authentic feel.

It's not cheap (for rakı, LOTS of meze, starters, small mains, and dessert, the bill came to about YTL 70 per person), but if you want to splurge a little bit, this is definitely a good place to do it.

There's also another branch in Kadıköy on the Asian side of Istanbul.