As previously mentioned, some TV shows count as Highlight Reels™ for much of their cast, while others are more like Milk Cartons™. It's the difference between being the best work of someone's career and effectively the last work.
For William Shatner, Star Trek is the Higlight Reel™. For DeForest Kelley, it's a Milk Carton™.
A show doesn't even have to be a big hit or cult classic to be the last stop for actors before they get their tickets punched for a one-way trip to Palookaville. Irwin Allen's Land of the Giants ran for two seasons. Like Star Trek, the production costs were very high for a TV show, what with all the odd sets that had to be built and special effects that don't look that special nowadays. Irwin Allen's big sci-fi hit was Lost In Space, but other shows like Land of the Giants and The Time Tunnel failed to find an audience and limped to the end of a season or two.
Not that the show doesn't have its fans. Blog buddy Dr. Zaius uses still shots from Land of the Giants as collage material occasionally, and personal cartoonist hero Tom Tomorrow outed himself as a fan of this piece of cheese on his blog.
If you are having a hard time recognizing cast members, you are not alone. From left to right, the front row is Deanna Lund, Stefan Arngrim and Heather Young, the back row is Don Matheson, Kurt Kasnar, Don Marshall and Gary Conway. Heather Young, the blonde, left the business and raised a family. Don Marshall was on two Star Trek episodes, and gets roles later in his career as Man on an episode of The Incredible Hulk and Slim's Henchman #2 in Uptown Saturday Night and Flight Engineer on Hardy Boys/Nancy Drew.
Stefan Arngrim, the kid, is still working to this day. You might remember his work as Druggie #2 on Dead Like Me or Cable Guy on DaVinci's Inquest or Hotel Clerk in Unnatural and Accidental.
Or maybe not.
I can tell you the reason both Land of the Giants and The Time Tunnel tanked. No sexual tension. Sci-fi and sexual tension go together like chicken and waffles. They had a pretty enough cast, but nobody was hitting on anybody. There was a little bit of a creepy vibe between Kurt Kasnar as the heel Fitzhugh and the kid Barry, but they decided not to go full on pedophile like Dr. Smith was with Will Robinson in Lost In Space.
Here is a publicity still of Deanna Lund with the miniature prop of the space ship the humans used to get to the planet where the the giants live. The scale on the giant planet is about 12:1, so this means there is a commercial space ship about forty feet long that seats a captain, co-captain, a flight attendant and several rows of passengers and has room for a very fancy engine that gets this thing airborne without wings. That may seem impossible to some of you people who studied, oh, I don't know... PHYSICS, but you have to remember that this is technology from the exciting and distant year in the future... 1983.
I should mention Ms. Lund's career after Land of the Giants. She was on an episode of Love, American Style. She was in a movie Jerry Lewis made in 1980, Hardly Working. She did settle down and marry co-star Don Matheson, but after they divorced, a career highlight mentioned in her bio is that she almost married Larry King, but they broke up and he married somebody else.
Nobody said being on a Milk Carton™ was easy.