My personal standouts have been:
NCL's Lamb Shanks: Only served at lunch in the dining room. Wonderful. The Norwegian Sky's were the best but on my last cruise on the Norwegian Star they were a bit fatty. Even then they were still "bone gnawing good."
Celebrity's: Mohr Em Hend: Viennese Chocolate Pudding. A delicious warm chocolate cake/pudding with heavy whipped cream.
Celebrity's Tornado of Beef Tenderloin with sauce Bearnaise: A standard but perfectly done.
Dawn Princess's, Sterling Steakhouse, Cream of Mushroom Soup in Bread Bowl: Sounds pedestrian but it was perfect.
Carnival's Turbot with Mixed Vegetable Puree Sauce: Out of this world. Perfectly seasoned fish and the vegetable sauces accented the fish and were fresh and not overpowering. They also made a beautiful presentation on the plate.
Then there was Ranch Steak on Serenade of the Seas: "The Horror: The Horror: The Horror"
( I knew it was bad but I had to try it.)