Radisson Plaza Cairns is one of the best (if not the best) hotels in Cairns. Location is great, right on the waterfront, next to a nice shopping center. Haven't seen the rooms there, but lobby is truly beautiful.

These links might be helpful:

http://www.radisson.com/cairnsau

http://www.photowebusa.com/pier-cairns/

http://www.great-barrier-reef.com/radissonplaza/

http://www.radissoncairns.au-hotels.com/

I have no doubt you'll enjoy Cairns tremendously!