I purchased a 3-day Hamburg card (free public transport and several discounts)upon arrival at the airport and made my way to Central Hamburg via the direct S-Bahn connection. Hamburg Hauptbahnhof is very big and very nice. There are lots of shops and food choices. It also can be a little disorienting popping out of there if you don't know which street is your destination. Thanks goodness for my iPhone -- I knew where my hotel was (close tot he station, so my trusty GPS function told me where I was.
There are no Hilton's in the Hamburg area. So, it was either a Fairmont or a Park Hyatt. I went with the Park Hyatt because it was closer to the train station (early morning departure flight to catch) and a little more centrally located. It's a very nice hotel. Even though I have no status with Hyatt, I was treated well. The rooms are nice, with plenty of space and 30 minutes of free internet every day.