Restaurant Fischstube, Bellerivestrasse 160, 8008 Zürich
http://www.fischstube.ch/
Prices are not cheap - at lunchtime you should expect to pay around CHF40-50 for a main course with water and coffee. There's a choice of several fish dishes such as Felchen (a white lake fish), Wolfsbarsch (sea bass) and Saibling (char) as well as other meat and vegetarian choices on the lunch menu, together with the Catch of the Day, which might cost you from CH45 to CHF65.
There's a good selection of tempting appetisers and mouth-watering desserts too. The wine list is extensive but also quite pricey. Our rose wine last month cost over CHF80 a bottle. Check out the menu at the link above.
This is a place for a special occasion due to its superb location. The food may sometimes be a bit disappointing - fish cooked simply in butter and herbs would be nice - but the experience of dining right on the blue waters or seeing the sun go down is unforgettable.