Side Hotel wins hands down.
Great little bar as well if you just looking for drink in the city.
http://www.side-hamburg.de/
Clipper Elb-Lodge Hamburg ist wirklich empfehlenswert nur leider auch sehr häufig ausgebucht, sehr gut geeignet für längere Aufenthalte http://www.clipper-hotels.de/framestarter.php?uebergabe=/elblodge/index.php
Clipper Elb Lodge Hamburg is a good place to stay, perfect for longer stays: http://www.clipper-hotels.de/framestarter.php?uebergabe=/elblodge/index.php
I stayed in Polo Novum Hotel near the main train station (don't worry it was so silent to have good sleep) they are also offering a very nice breakfast buffet and small Haribo packs on your bed. :-)
You can click here http://www.hotel-hamburg-zentrum.de/ and see the other options that Novum Hotels is offering for you in Hamburg.