MK- Columbia Harbor House (sit upstairs... it's as relaxing as a CS can get)
AK- Flame Tree has the best CS food there (but there is no inside seating and there are birds)
EC- Sunshine Seasons has good food and good variety
DHS- Do either Sci-Fi or 50's for a TS lunch. Not a fan of any CS there.
Check out the menus:
http://allears.net/menu/menus.htm
With a little research and planning you could go to WDW for quite a long time, eat nothing but CS and not have to eat a single burger, fry, slice of pizza or chicken nugget.