Yeah, my overall list changes, depending on the day. Today, I'm feeling like every series should be represented, so in air date order, it is:
- TOS: The City on the Edge of Forever
- TOS: The Doomsday Machine
- TOS: Journey to Babel
- TAS: Yesteryear
- TNG: The Offspring
- TNG: Sins of the Father
- TNG: Darmok
- VOY: Real Life
- DS9: Far Beyond the Stars
- ENT: Horizon