Connoisseurs of bad taste have rarely a dull week when it comes to television, but tonight ABC truly out-camps even itself with "The General Electric All-Star Anniversary Special" at 8 on Channel 7.

This is the kind of fat and plastic pageant that the city fathers of Sinclair Lewis's Gopher Prairie might have thrown together for the Fourth of July if someone had given them two hours of network prime time and about a half-million bucks. The show is not bad beyond belief - since there is considerable precedent within the last 30 years of television - but it is bad beyond all sense of decency.

To celebrate its 100th anniversary, the General Electric Co. hired Paul W. Keyes, Nixon's old gag-writer, to produce a platitudinous plod through our nation's past that features the inevitable retinue of tired ABC series stars (John Ritter, Donny and Marie, Laverne and Shirley) plus some celebrated pieces of living crockery like Henry Fonda, James Stewart, Elizabeth Taylor and Red Skelton, with John Wayne. Mt. Rushmore himself, as the host.

A high point occurs when Hollywood-liberal Fonda stalks out to bury his hatchet with Wayne over the Vietnam War. Surely the '60s have ended more times than any decade in history, and here they are ending again.

An because it would be considered upatriotic in showbiz circles to unfurl the flag without Bob Hope on hand, Hope appears in the second hour to deliver a standard snappy monologue and to declare. "I'd still rather have a bad year here in America than a good year anywhere else."

It took Keyes and three other writers to compose such exquisite observations for Wayne as "Well, there it is, planet Earth - home of every man, woman and child that ever lived." World War II sounds kinda wonderful: "It was anchors aweigh as we flew off into the wild blue yonder, and just like this great country, the music went right along with us."

How strange that GE, whose TV commericals, on this show and others are relatively exemplary, would decide to interrupt the with such an amateurish boosterist marathon as this. The Americana of it all is dubious at best - Cheryl Ladd doing a disco version of "Baby Face" as a salute to vaudeville, or Suzanne Somers, that inescapable and talentless oaf, jiggling through a disco version of "Yankee Doodle Dandy" as a salute to show boats.

Pat Hingle, who has played Thomas Edison in series of GE ads, looks decimated and demeaned when he has to shuffle out near the show's conclusion to shake the Duke's hand tell him what a grand American he is. The dignity Hingle demonstrates in the commercials is undone by Keyes' loathsome notion of nation-stroking entertainment.

The one bright spot in the show features, of all morbid ironles, repeated shots of an exploding H-bomb. Ethel Merman's recording of "Everything's Coming Up Roses" is played under a 3-minute newsreel montage of the '50s. At the line "I can tell" we see Sen. Joseph McCarthy and on "wait and see," Edward R. Murrow. Then the bomb goes off for a finish, and in these surroundings, there's something about it that seems insanely refreshing.