Synopsis: During a recreation of the Ancient West, the holodeck safety guards fail. In other news, the Enterprise crew have free time and several officers almost die.
Memory Alpha Summary: And nobody calls Data yellow.
Review: Does anybody on the ship ever get to enjoy their down time? Anyway, the holodeck malfunction is very contrived, but fun all the same. Hearing Data tell Spot, “Vamoose you little varmint!” is hilarious, as are Spiner’s other antics on the show. Alexander isn’t too annoying, and Worf actually gets to kick some ass for once. Too silly to be tense, but a nice diversion.
Death By Troggles 
Here we are…the very first one that I remember strongly from when I was watching this show with Natalie in 1996. Because I barely knew the characters yet, it had much less impact than intended, but I still dug the hell out of it.
Yup, this one is a classic standalone episode. Sure, it’s yet another “what would happen if the holodeck malfunctioned in exactly this way?” episodes, but it’s one of my favorites among those.