Jägerhof is without doubt the finest restaurant in St. Gallen town. The owner Vreni Giger was rated best female cook in Switzerland some years ago and has received 17 points form Gault Millau. www.jaegerhof.ch
Not far from St. Gallen there are two other great restaurants:
Gupf, Rehetobel (1 michelin star)
Neue Blumenau, Lömmenschwil (young chef Nenad Mlinicevic is a rising star)
I think that TA is a great source of information and I always check the hotel reviews before I book a trip. However with the restaurant recommendations I've had mixed experiences and sometimes there are really strange ratings. For example in Zurich no. 1 is a Chiang Mai Thai Shop - certainly not the finest restaurant in town!