Where to Eat in St Petersburg

sfumato is right, you should avoid the really expensive places and avoid the places where you hear no Russian.
The Stolle pie shops are terrific- they make traditional Russian pies with a huge variety of fillings (lots are veggie-friendly). There are several around town.
Kilikia Armenian restaurant is very good. they serve Armenian as well as pizza. I had some sort of soup with greens that was amazing. And around the corner from it is a total hole-in-the-wall Chinese place that's good and very cheap with nice Chinese waitresses.
For the love of all that is good and holy, skip the Idiot, which was a funky, cheap vegeterian place about ten years ago and now is overpriced and expat-oriented.
Definitely have some Georgian food while you're there. Lagidze on Ulitsa Belinskogo is good. I'm not sure if any English is spoken there or not.
Check out the St. Petersburg In Your Pocket guide for up-to-date restaurant info. Much better than Lonely Planet.

ziejoy in Europe