Bergen is great,but VERY expensive,take the cable car up to Floyen to see the view over Bergen,the Flybussen bus is fast in to town from the Airport,you can buy tickets online.
I found Copenhagen dirty and boring,was happy to leave,but if going to Copenhagen,take the train over the Oresound bridge to Malmo in Sweden,great experience,plus you get to visit another country,no passport checks on the train.