I was originally going to go to Hamburg 2 weeks ago, to meet up with a friend who would also be in Hamburg. Unfortunately, I could not get any accommodation (apparently it is the peak of the backpacker season). The train ticket was valid for a full month, so I planned better, and spent the past weekend in Hamburg.
I was quite lucky to make the train I wanted ... if it was on time, I would have been late by about 2 minutes. I was getting off the local train when the train was scheduled to leave. Luckily for me, the train was running late (by about 10 minutes) and I managed to catch it. The scenery was rather bland - miles of green farm land dotted with a lot of wind power stations. But not much else to see.
I stayed at the Instant Sleep Hostel, which is in a convenient location to move around Hamburg. Paraphrasing the Lonely Planet guide, it is a colourful hostel, but with very sparse facilities. I stayed in the hall of dreams, a 25 bed dorm! Have no complaints of the actual hostel really, although there was no such thing as an atmosphere. But then, I needed a bed to sleep in, and did not intend to hang out in the hostel.
Hamburg is really known for three things: its massive harbour, the airbus factory and Reeperbahn. Reeperbahn is the red light district, even larger than Amsterdam. It is reputedly a lot tamer (I need to investigate this), full of neon lights and at times, quite amusing (the reaction of people walking through, the ads etc).
As for the harbour, you only really understand the scale and size of it if you take a river cruise (or in my case, take the public ferries). The size of the ships is simply staggering, and the harbour is quite busy.
I did not see the Airbus factory, but it does seem that not everyone is impressed with the new plane.
Hamburg was an independent state for a long time, and it was quite a rich state at that. The city hall's impressive architecture is testament to this. I was there too early in the morning, and thus could not go inside.
St. Nikolai Church was one of the largest churches before WW2, and was then bombed. The spire is more or less all that remains, and is now an anti-war memorial. Again it was too early in the morning, so everything was closed. I did go up the tower of St. Michaelis Church though (it opens earlier than the others) and it offers a fantastic view of Hamburg, but is not as interesting.
For me, there were actually only two highlights on my trip: the Olympic Rolercoaster at the Hamburger Dom (a fun fair), and the Fish Market. I haven't been on many roller coasters, but The Olympic Roller Coaster has been by far the best. The 5 rings are complete loops and it is an amazing ride. The photo is from the tower of St. Michaelis; I did not actually take photos of either the Hamburger Dom or Reeperbahn.
The fish market is an open air market, and not much fish gets sold anymore. Even though I don't understand German, it is the antics of the stall keepers that is really impressive. Many put on a real show, in order to sell their wares, and there are some real bargains to be had; such as the full basket of fruit and vegetable (including the basket) for 10 Euros, to trees and plants for the garden.
Hamburg is also well known for its live music scene, especially for being the "birthplace" of the Beatles phenomenon. Just my luck: there are two music festivals starting this coming weekend, and there was one the weekend before. But this past weekend, there were only a few acts in bars and the like, and all the ones I found tended to be solo guitar acts, so I just kept looking (without much luck).
To be honest, there is nothing special about Hamburg. But if you do go, make sure you get up early on Sunday morning to go to the Fish Market.