I've been to Big Fish a few times and I have yet to be disappointed. My spouse and I have come for the Monday oyster special, and loved the suggestions the server had for us as well as their explanations of the oysters.
We have also been for a full meal and everyone left satisfied. The platter is a great starter to share and a good way to try a few different types of fish. The arctic char dish is great, as is the pickerel. The wild salmon was yummy, but there are better dishes on the menu.
The service was satisfactory, but I wasn't blown away. But overall a great restaurant with great food and a nice atmosphere.