craz...Agree that in certain areas of Europe Radisson is the way to go as the other big hotel chains have a limited presence. For the certificate redemptions I think in the the US the best options for a "good" Radisson are probalby the following unless you find a CI&S that is in a location where the price goes crazy for a special event:
NYC - Cassa and Martinique (which is to leave RR)
Chicago - Radisson Blu
Minneapolis - Radisson Blu and Radisson Red
Melbourne FL - Radisson Suites Oceanfront
Toronto Harbourfront