I have one single criteria to differentiate between okay food, and food that I love.
It does not matter if it is something I make myself, eat in a dive hole in the wall, or in a 5-star restaurant.
When I eat out, there is usually also the additional, incidental criteria, that I cannot decipher exactly how they made this deliciousness. ie the food is more delicious then the sum of its parts/ingredients.
Perhaps I am just reiterating the Chowhound credo in different words, but when I have that certain morsel of food that is really excellent the term I use to describe it is that upon eating it, "I hear the angels sing."