The Galata Bridge is stuffed with cafes and restaurants and most of them have tiresome touts trying to make you choose them ('Yes! hello! Speak english!? You try my restaurant!') . We enjoyed a walk across the bridge and chose yagalata on the way back - the fish looked good and the prices were clearly marked on the menu.
The waiters constantly try to upsell you in the crudest way and when we asked for the wine list, the cheapest was the equivalent of £35 GB! We simply said we would have none as it was far too dear ('What dear!? Is no dear. You have wine?!)
We had a sea bass and shared an octopus salad - the sea bass was very good. However an extra green salad appeared on the bill, which we pointed out and after discussion was removed. We paid 47 YTL for the meal which was OK, but given the hassle we would not go back given the opportunity and I would forwarn other travellers to be ultra careful and as hard-faced as the waiters are.
Favorite Dish: The small sea bass was delicious and filling. The Octopus was like a drownedman's fingers, which I suppose might be deemed attractive to some.
I found this place following my usual rule: go where the locals go. The Galata bridge is full of touristy and pricey places, but here I had two grilled fish (yes, two!) for about 20 million liras, which isn't bad at all. Beer is also cheap-ish and service is swift. Too bad the view is on the wrong side, but the dark sea has some fascination. Recommended.
Favorite Dish: Grilled "cupra" (sea bram)
You can buy fresh fish sandwiches from the boats just near Galata Bridge, on Sultanahmet side. They're excellent and cheap (around EUR 1 per sandwich) and highly recommend them. I kept coming back there during my stay in Istanbul.
By the Galata bridge, in Eminönü, you can buy sandwiches with grilled fish from small boats. It is very tasty (and greasy) and cheap. A fish sandwich cost 1 500 000 TL.
I bought another deliscious fish sandwich (that also had sallad, tomatoes and onions) in Anadolu Kavagi.
Surely never done this before. Go to Eminonu Port and strall along the waterfront. Wonder why it's so crowded? Local fishermen come at the end of the day to sell the catch of the day. Grill fish on a bagette. Help your self to some lemon juice and salt.
Find an empty seat and join the locals. It is so yummi you wil lick your fingers. ;o)