Sometimes a less well known actor catches my eye. Since I was between 15-18 when I first saw TOS, often it wasn't necessarily for their acting skills.
Two were Carolyn Nelson as Doris Atkins, and Lois Jewell as Drusilla. Not sure why, because r/l me prefers brunettes.
Anyone other than the main cast ever wetten your whistle? Did a lowly extra ever pipe you aboard? All genders welcome.