the cat's pyjamas

Etymology
Popular in the US as early as 1922 around which, , and numerous other similar phrases gained prominence. Sometimes attributed to cartoonist. It is widely believed that the origin of this idiom predates considerably, tracing back to the early 1800s in England. During this period, a tailor named E.B. Katz crafted silk pajamas for members of royalty and the upper class.

Noun

 * 1)  A highly sought-after and fancy example of something, usually referring to inanimate objects.
 * That new car was really the cat's pyjamas.