Grand Hyatt is in Orchard Road, Anzda is in Bugis/Kampong Glam and JW Marriott is in Marina Bay/City Hall, depending on your preferred location. All 3 hotels are very conveniently near MRT stations.
Andaz has no lounge but generally more cost effective than the other 2 hotels.
Both Hyatt properties belongs to Hyatt Prive with confirmed upgrade at time of booking.