We enjoyed our stay at the Waldstaetterhoff located a short block from the train station and very walkable to the bridge and old town.
http://www.hotel-waldstaetterhof.ch/en/
The Monopole is even closer to the train station and gets good reviews.
For attractions a bit farther than walking, the hotel gave us a free Visitors Card.
http://www.luzern.com/en/visitors-card
The Visitor Card is available to you during your stay in the
Lucerne-Lake Lucerne Region. Your hotel will be pleased to issue you
with the necessary documentation and links.
The Visitor Card gives you free use of buses and trains within zone 10
of the city network, as well as a range of discounts for cableways,
mountain railways, museums and excursions in the Lucerne-Lake Lucerne
Region. You can also take advantage of ‘Free WiFi – LUZERN.COM’
hotspots dotted around the city.