Via dangerousmeta: Jonathan Harris dies at 87. Sure, Lost In Space was corny, but not everyone knew this. When Gene Roddenberry was still alive, he toured colleges with footage of early Star Trek episodes and bloopers. I saw him at Michigan Tech, where he related that when he was trying to sell the show, CBS told him "we already have an adult science fiction show." Still, I had a king-size crush on Penny Robinson, and Dr. Smith was always fun, even though the 'comic' version was not as much fun as the first few episodes.
Ironically, Harris died of a blood clot while receiving treatment for back problems (Dr. Smith's perrenial excuse from work).