I think Melakon, in the initial post, was asking about people with very small roles, not the guest stars. We allllllll know about wonderful Sherry and Leslie. Who else, though, the ones with just a few lines, or none at all?
Yes, I was thinking in terms of all those walk-ons and one-line players who rarely get any attention. But with a topic like this, it's going to stretch in different directions. I'm also curious if female members here had a similar crush on random redshirts. David L. Ross (Galloway) was one of the more frequently seen, but a lot of redshirts were really athletic stuntmen like Jay Jones, who memorably stepped on an exploding rock in "The Apple"(the stunt put him in the hospital).
EDIT: Better looks at the women I posted:
Carolyn Nelson in "The Deadly Years"
Lois Jewell in "Bread and Circuses"