He's one of my favorite writers. I would say, assuming you are reading in english, be careful with what translation you get. Hunger, pan and mysteries are all great youthful book. I saw an other comment here about the downfall of readership due to his Nazism. Well according to my grandfather people refused to burn Hamsun's books even if he was viewed as a traitor, that should tell you how good he was viewed. Or the fact that he is still taught in school and considered one of our countries best authors still. He was totally unapologetic to his betrayal and Nazism. His last book was written to prove he wasn't senile, which government doctors had come out and official said he was mostly to save his reputation. I think it's called on overgrown paths in english

Growth of the Soil and Victoria didn't really do it for me, but I quite liked Mysteries, and Hunger and Pan are both masterworks. If you like him, I strongly suggest Par Lagerkvist for more Scando-misery.

Hunger was good, but I've read it so long ago I only remember the vague impression it left on me.

Both are great, but I like Mysteries even more. I haven't read his later stuff but Hunger, Mysteries and Pan are all thrilling and ahead of their time. He went a bit crackers later in life and was a Nazi sympathiser which seems to have reduced his readership these days.