Doris - I'd probably pick:
the Ritz-Carlton Osaka
http://www.ritzcarlton.com/hotels/osaka/
http://www.tripadvisor.com/Hotel_Review-g298566-d302242-Reviews-Ritz_Carlton_Osaka-Osaka_Kinki.html

or

the Rihga Royal Osaka Hotel:
http://www.rihga.com/osaka/
http://www.tripadvisor.com/Hotel_Review-g298566-d302408-Reviews-RIHGA_Royal_Osaka-Osaka_Kinki.html

or

Hotel Nikko Osaka:
http://www.hno.co.jp/english/index_e.html
http://www.tripadvisor.com/Hotel_Review-g298566-d302313-Reviews-Hotel_Nikko_Osaka-Osaka_Kinki.html

All of these hotels are chosen for their reputation and their location - usually located within easy walking distance/free shuttle bus/built right above (!) major train stations.

I'm still trying to figure out where we're going to stay for precruise PANDA ... :)

Masaki