The shuttlecraft Galileo, carrying Kirk, Spock, McCoy, and Federation Commissioner Nancy Hedford, is drawn to a small planet by a mysterious cloud, which turns out to be a creature that has been caring for shipwrecked warp drive inventor Zefram Cochrane.
Air Date: 11/10/67
Director: Ralph Senensky
The first appearance of Zefram Cochrane is one of the earliest episodes of the original series I remember seeing when I was a kid. In fact, I remember seeing the companion on screen and asking my step-dad what it was, which hooked me into watching the episode! I love this one because of Elinor Donahue as well - Ellie Walker from Andy Griffith! While her character is rather irritating (on purpose) the rather sweet ending more than makes up for that.