According to Wikipedia, the well-known catchphrase of the Robot in Lost in Space, "Danger, Will Robinson!" is only uttered once in the three seasons of the show. Though the Robot was known to frequently warn of "Danger! Danger!" to no one particular family member.
So I'm wondering, is there any clear source from which its status an an iconic scifi catchphrase originates (e.g., a popular referential usage in another TV series or movie, etc)? I know that the 1998 film adaptation used the phrase prominently in its advertising – and presumably in the film, though I haven't seen it – but I was aware of the phrase before this, despite having not seen the original series either, so I feel there must be an earlier source for its popularity.