There's supposed to be a lot of bars and pubs near the old harbor, the old town area is full of small streets and shops. St Pauli and Beck's are from Bremen (not sure if they still brew some there). The townhall is a UNESCO site and there is a bronze sculpture of the animal musicians that are in that fairy tale.
Tell me know how you like it. I was supposed to go there and then down to Cologne two summers ago but couldn't find the rest of my Eurorail pass so I had to give it up.