City Hotel is in the heart of town. Good enough place to stay. It's around the corner from a very good Chines/Tapas restaurant, close to shopping and Forum Concert hall, night clubs etc.
the City hotel is very good and central, http://www.cityhotelderry.com/ .
if you want a cheaper alternative, the travelodge is also central [broken link removed]
City Hotel is the place to go. Right on the river next to the new footbridge. Walking distance from anywhere in the city centre. Close to the bars and clubs.