I usually find that if a line offers filet mignon that is an excellent choice. Azamara had one of the most excellent chef's dinners I have ever experienced.
I have also tried chef's dinners on Holland America and Norwegian Epic and both were very good.
I find the food in the alternative restaurants on NCL to be surprisingly good - especialy Moderno the Brazilian Churasscuria.
We tried the Lawn Grill on Celebrity and that was also really outstanding. It always really is a treat when you can get something fresh off a grill on a cruise ship.
In Alaska on HAL last month the grilled salmon at the outdoor lunchtime buffet was the best I had all week.