Munch is great. I saw a bunch of his (less famous) works at Thiel Gallery in Stockholm. Always appreciated his work but consider myself a fan after seeing it in natural light. Can see the influence from Van Gogh and Gauguin, but the soul he puts into his works seems anticipatory of the Surrealists and similar movements which prioritized emotion and psychological exploration over precise realism.
Of all the work I've seen it swings wildly from fine landscape to abstract and horror, to portraits and the surreal. If I didn't know they were all Munch I wouldn't believe it ;)
I visited Bergen (which has a great gallery) but unfortunately couldn't travel as far as Oslo for a day. The entire country is up down, east, west, up down, back on yourself to get anywhere (unless sea or plane!