First class
First class was a term used to describe a high tier of quality of one's travel or living arrangements.

In 2152,  apologized to Rellus Tagrim for having to settle him, Guri, and Renth in 's catwalk, saying they weren't first class accommodations, but Tagrim assured him they would do. ()

When Harry Mudd was left behind by Captain James T. Kirk on Planet Mudd under the continued care of the Mudd androids in 2268, Kirk informed Mudd that "You'll stay here and provide a first class example to the androids of a Human failure. They'll learn by close observation how to avoid ones like you in the future." ()

See also 
 Crewman first class
 Midshipman first class
 Spaceman first class
 Technician first class

Slang