I find it hard to pick just one... even 5. I'd have to list several by category.
Action: "Balance of Terror", "Mirror, Mirror", "The Corbomite Maneuver"
Story: "City on the Edge of Forever", "The Menagerie", "Journey to Babel"
Humor: "Shore Leave", "Whom Gods Destroy", "Plato's Stepchildren", "The Squire of Gothos"
Intrigue: "All Our Yesterdays", "Requiem for Methuselah", "Patterns of Force", "The Savage Curtain"
The "Intrigue" category is for episodes that I thought had really terrific ideas that could have made them "top 5" episodes, but fell short in several ways.
Action: "Balance of Terror", "Mirror, Mirror", "The Corbomite Maneuver"
Story: "City on the Edge of Forever", "The Menagerie", "Journey to Babel"
Humor: "Shore Leave", "Whom Gods Destroy", "Plato's Stepchildren", "The Squire of Gothos"
Intrigue: "All Our Yesterdays", "Requiem for Methuselah", "Patterns of Force", "The Savage Curtain"
The "Intrigue" category is for episodes that I thought had really terrific ideas that could have made them "top 5" episodes, but fell short in several ways.