You should watch all of Deep Space Nine, but if you don’t have the patience to sit through the unnecessary episodes (and perhaps you’ve heard how cool DS9 becomes), here is a list of the episodes to watch from season one:
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Emissary: Parts 1 & 2 Rating: 4 – Watch
Past Prologue Rating: 3 – Watch 
A Man Alone Rating: 3 – Watch 
Babel Rating: 2 – Skippable
Captive Pursuit Rating: 3 – Watch 
Q-Less Rating: 2 – Skippable
Dax Rating: 2 – Skippable
The Passenger Rating: 1 – Skip
Move Along Home Rating: 1 – Skip
The Nagus Rating: 2 – Skippable
Vortex Rating: 2 – Skippable
Battle Lines Rating: 2 – Watch for continuity
The Storyteller Rating: 1 – Skip
Progress Rating: 1 – Skip
If Wishes Were Horses Rating: 1 – Skip
The Forsaken Rating: 2 – Skippable
Dramatis Personae Rating: 1 – Skip
Duet Rating: 4 – Watch
In the Hands of Prophets Rating: 2 – Watch for continuity

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