Ah, this was hard!
10. "I, Borg"--TNG
9. "Lower Decks"--TNG
8. "Children of Time"--DS9
7. "Observor Effect"--ENT
6. "Inner Light"--TNG
5. "Measure of a Man"--TNG
4. "City on the Edge of Forever"--TOS
3. "Duet"--DS9
2. "All Good Things..."--TNG
1. "Living Witness"--VOY
I wasn't trying to spread that between the series, but it looks like I ended up with quite a mix anyway.