We went to Kastenmeiers for a 65th birthday dinner and had the most wonderful time (we stayed for four hours!).
The restaurant is right in the middle of the old town, near the Frauenkirche, housed in "Dresden's last ruin" (only renovated in the last decade).
We paid about EUR 100 per person for a truly exceptional meal (4 courses and wine) - less than we had expected. The setting inside the Kurland Palais was splendid, but what made the visit really worthwhile was the staff - even on a Saturday night, the barman took time to show off his wine collection and let us choose; the waitress took real pride to recount the story of the Palais and elaborated on the available menu choices; and other passing waiters stopped more than once to show off the amazing fish concoctions on their way from the kitchen to their respective tables. It was clear that everybody was having fun working there, and took pride in sharing this with their guests.
Would always recommend this for a special occasion.
Oh, and by the way, Kastenmeiers do business lunches for an incredible EUR 9.90 during the week (and 19.90 on weekends).