Unfortunately, there weren't many reviews on Zurich eateries before we went so we asked expats where to go and were happy with their suggestions.
CAFE SCHOBER, like many restaurants in Zurich, has been around for over a century. We stopped by for some house-made hot chocolate while walking around the old district on our way to visit Fraumunster & Grossmunster. Good hot chocolate, but not quite as decadent as the one we found at Florence, Italy's Gilli. Worth a stop for the old, cutely decorated interior.
ZEUGHAUSKELLER is a great place for lunch, with huge (for Swiss) portions. If you don't have a reservation, time your visit carefully as you can hit the line which goes out the door. Prices are reasonable (for Switzerland). Most sausage dishes come with a delicious potato salad. Make sure you have a beer too.
HAUS HILTL is the oldest vegetarian restaurant in Zurich. While we ordered off the menu, the better idea was probably to hit the buffet so you could sample many of their offerings. Moderate/pricey, it's worth a visit if you like veggies. Swiss Air's vegetarian dishes are made by Hiltl.
Everything we ate, was so very, very good. Even the tap water (compared to Southern California) was delicious--better than most of the bottled versions.