Serta is the best-rated manufacturer of mattresses, including king size beds, according to Consumer Reports. As of 2014, Serta's Perfect Sleeper has been a Consumer Digest Best Buy for 14 years and is endorsed by the National Sleep Foundation.
Serta's Perfect Sleeper mattress line was developed in conjunction with the National Sleep Foundation to correct sleep problems, and it is the only official mattress of the foundation. The Perfect Sleeper, an innerspring mattress, can be used in a typical, static king size bed frame or on one of Serta's adjustable platforms.
In 2012, the company's iComfort bed was also named a Consumer Digest Best Buy. The iComfort mattress by Serta uses a mixture of memory foam and gel to provide support, explains Consumer Reports.