Since I'm from Denmark, this is quite simple to answer from a Danish point of view.
The languages of Danmark and Norway are almost the same. Pronounced in the same way, and almost written in the same way.
The next closest similar to Danish is Swedish. It's a bit difficult to listen to, but after some time, you're getting what they are saying*s*.
Then the last one is Finland. For us danish people it's complete rubbish to listen to (if you can't talk Finish). They have something with their rrrr--- in words, more lide Schwitzerland.
Hope that made something clear.