Well there will probably be a variety of answers, depending on how you mean it.
If you say "Good Work" as a praisal of some good work done, you just say "Godt arbejde". It is just the literally translation actually.
They say godmorgen.
Good Morning.
"Godnat"
You can say "Hav en god dag" in Danish to mean "Have a good day."
det var godt
Hvordan er dit arbejde?
Det her er mit arbejde.
"Det lyder godt"
spiser edderkopper
Er den bog god?
Min dag er god.
"No" in Danish is ingen