Lost In Space:
Space Beauty
Original Broadcast: 14 February 1968
 
Farnum B returns, this time at the helm of an intergalactic beauty pageant. The combined of wiles of Farnum and Smith finally convince a reluctant Judy to sign up for the pageant. To everyone's horror, the fine print reads that the winner of the pageant will live in a far away galaxy with an evil monarch composed of fire!
Not only the single highest rated episode in the entire series, but a spectacular showcase for Marta. And on Valentine's Day to boot.
 
Marta reminisces about this episode on Ray Dutczak's LIS Memories Website.