The New York City Opera's revival of "The Pajama Game" is the best of its stagings of golden oldie Broadway musicals and a successful finale to Beverly Sill's 10-year career as general director of the company.

Sills has not always been so successful with these revivals, which she calls the company's Musical Comedy Season, now in its fourth year. "Brigadoon" and "South Pacific" were disappointing and "The Music Man" was just a cut above a good stock company production. Fortunately, "The Pajama Game" has much of the pizzazz of the original 1954 staging.The revival, which opened last weekend to run through April 16, marks Sill's last NYCO production before her retirement next week. Altogether she has served the opera company 34 years as singer, prima donna, chief fund raiser and director, a unique career in the annals of American musical history.

Unlike Sills' revivals of musicals like "Kismet" and "Candide" which have been done by company singers as part of the company's regular season, the Musical Comedy Season imports Broadway singers for principal roles. This is a wise policy, because voices trained for opera usually do not have an authentic musical comedy sound.

For "The Pajama Game" she enlisted the talents of Judy Kaye, fresh from "The Phantom of the Opera," Richard Muenz, Lenora Nemetz, and Avery Saltmzman for the leading roles and they turn in delightful performances.

Kaye may be a little too old for the role of Babe, originally taken by Janis Paige, but her lilting soprano and warm personality make up for that, and she is nicely matched by baritone Muenz, her handsome and believably romantic suitor in the John Raitt role of Sid Sorokin.

Nemetz is a sassy vocal belter, a zany comedian, and an outstanding dancing talent in the ingenue role of Gladys, which made Carol Haney famous and brought her stand-in, Shirley MacLaine, to Hollywood's attention. Saltzman is a one-man laugh machine as Hines, the low comedy role taken by Eddie Foy Jr. in 1954.

Also worthy of mention in supporting roles are David Green, Steve Pudenz, and Brooks Almy, a Broadway and City Opera veteran who scores in her duet, "I'll Never Be Jealous Again," with Hines.

Strangely enough, "Pajama Game" doesn't seem particularly dated, dealing as it does with a labor dispute in a week when the Eastern Airlines strike is making headlines.

Babe, a worker at the Sleep-Tite Pajama Company and leader of the union grievance committee, and Sid, the new factory superintendent, fall in love only to have the employes' insistence on a 71/2-cent-an-hour pay increase put them on opposite sides of the bargaining table.

Sid decides to settle the dispute by wangling the key to the safe containing the company's books out of Gladys. The books show the company already has added the 7 1/2 cents to their costs and forces Sleep-Tite's president to give the workers their raise.

The book by George Abbott and Richard Bissell, based on Bissell's novel, "Seven-and-a-Half Cents," is serviceable enough and the music by Richard Adler and Jerry Ross, a star-crossed team broken up by Ross's premature death, has the coarse-grained, ebulliently melodic sound of the 1950s. Conductor Peter Howard pulls out all the music's stops.

There are 17 musical numbers in this show, all pleasant and several of them - including "Steam Heat," "Hey There" and that tango classic, "Hernando's Hideaway" - deserving of their status as Broadway hits. One of them, the "Jealousy Ballet" is neatly danced by Nemetz with partners representing such film heroes as Elvis, Zorro, Marlon "Wild One" Brando, and Kirk Douglas in "Spartacus."

Set creator designer Michael Anania has lavished mint greens, candy pinks and other exuberant colors of the '50s on his attractive sets, especially the picnic grounds scene. His deftly depicted factory setting for the sewing machine brigade and the mock-sinister cafe for the "Hernando's Hideway" scene are minor design masterpieces.

Costume designer Marjorie McCown has recreated the look of era to perfection - shirtwaist blouses and poodle-appliqued skirts, Madras plaid trousers worn with baggy pants, saddle shoes, hairbows in beehive coiffures, and sunglasses.

The pajama fashion show in the final scene is a celebration of vulgar design that passed for chic when President Truman wore aloha shirts.

Theodore Pappas has given "The Pajama Game" lively and purposeful direction, never letting the show drag as revivals are wont to do. Pappas doubles as choreographer, providing dance numbers that are indebted to the original Bob Fosse-Jerome Robbins choreography without being recreations.