Incredibly sad and unintentionally funny - Voyage to the Bottom of the Sea had a great starting premise. It would have made an awesome Cold War espionage show! Then Lost in Space Lobster monsters, Blackbeard's Ghost firing nuclear missiles, etc. And worse, Lost in Space earworm sound effects that you never forget.
Lost in Space gets a partial pass for 8 year olds - I liked it then.
Irwin ruined lots of acting careers : /
In fact I think SeaQuest also used nearly the same premise (& also got silly toward the end).
I ALWAYS think of these Irwin Allen shows every time I hear about Hollywood wanting to do a serious SF / Fantasy movie.
Thank you to Peter Jackson, who proved you could do a serious Fantasy movie without Hollywood BS. I kind of think he pointed the way for movies like "Arrival" and the latest "Dune" to be made seriously and to the novels.