Taking all of Trek as canon (so you can't leave out Enterprise or the animated Trek as much as you may like to), which episodes are essential to the continuing story of Star Trek?
For example, you need to watch TNG The Emissary, otherwise when you watch Reunion, you'll be saying, "Who is that Klingon woman?"
And no fair saying, "Let's just leave out particular story arcs altogether." The episodes that make up the essential Trek include all the good eps (City on the Edge of Forever, Yesterday's Enterprise and all that), the story arcs (even the ones in DS9 that mention the Dominion just in passing that set up the introduction of it later) as well as the great character episodes like Duet and The Inner Light.
So what episodes are on your list, and why?
For example, you need to watch TNG The Emissary, otherwise when you watch Reunion, you'll be saying, "Who is that Klingon woman?"
And no fair saying, "Let's just leave out particular story arcs altogether." The episodes that make up the essential Trek include all the good eps (City on the Edge of Forever, Yesterday's Enterprise and all that), the story arcs (even the ones in DS9 that mention the Dominion just in passing that set up the introduction of it later) as well as the great character episodes like Duet and The Inner Light.
So what episodes are on your list, and why?