I loved the episode “Where Silence Has Lease” from season 2 episode 2.
It was exciting in a frustrating way, for we feel the same amount of frustration and anxiety in not knowing who or what is holding the ship captive while toying with the crew like lab rats. The crew undergoes an attack by a Romulan ship that is easily destroyed by the enterprise’s weapons (not a true scenario) and another starship that’s configurations are like a maze that does not coincide with an actual star ship.
One highlight is when the entity we are introduced to more than half way through the show, who calls himself Nagilum, asks for a demonstration of how the male and female life forms procreate and throws Dr. Polaski half way across the bridge.
It also wants to explore death and the various ways in which the human species will die. At this point, Wesley Crusher, who was on the bridge at the earlier time, has now been replaced by an ensign Haskall. Nagilum destroys Haskall to death internally and our poor hapless ensign falls in a fetal position with eyes wide open to suggest a torturous death.
After seeing this entity’s capabilities, Wesley is now back on the bridge and the Picard and Riker cancel the auto destruct sequence they implemented after they believed Nagilum was going to practice death techniques on random crew members.
It always drove me nuts, even with the original series, how they'd bring out this crew member we'd never seen before just to be put to death by the entity. Then the star crew member is brought back and things continue as normal. We see this in the first season of TNG as well, when an engineer is electrocuted by an entity through the control panels and the bridge crew, including Counselor Troi, acts like it didn't happen. That episode was called "Lonely Among Us" and one of the worst episodes of the series.