A great place to go is the Coral Reef in Epcot. The food, service and atmosphere is great and you can't beat the value when you do it on the dining plan.
I'd personally never use 2 TS credits for a signature restaurant. I'd either go to Coral Reef and use 1 TS credit or pay for Flying Fish out of pocket.
Using 2 TS credits for a meal just isn't a good value.
We are planning on trying the buffet at Cape May at the Beach Club. I have heard good things about it so we are giving it a try. We have a couple family members who are not big on fish and they have ribs at the buffet also. Also with teenage boys they can eat their fill at a buffet and there is plenty to choose from.