Next best thing
IC Royal Ambassador is great. 2 level upgrade, free internet, free mini bar (drinks only), free health club access, BOGO weekend certificate and ease of earning bonus points for free nights. Issue is limited number of ICs around the world. New policy is reducing the value of stays at crowne plaza's etc in order to maintain RA status. They used to include non IC hotel towards maintaining status.
Hyatt diamond is a good program, but also has limited hotels.
Based on the above, Starwood is probably the best bet due to the large number of hotels they have worldwide, although I feel the other 2 offer better benefits for top tier customers. The last devaluation of points made me leave the program. Good hotels are available, but earning potential for free nights is limited in comparison to the other 2.