Good ones:
* Moving Still (1980); development of <film> technology
* Race for the <Superconductor> (1988): recounts the feeding frenzy for <high-temperature superconductivity> after the Swiss found a ceramic superconductor.
* The Proof (1997): <Fermat's last theorem> 
* Absolute Zero: The Conquest of Cold (2008): <cryogenics>

Best one lists:
* https://www.reddit.com/r/Documentaries/comments/17ygzq/what_are_some_of_the_bestyour_favorite_nova/
* https://www.reddit.com/r/askscience/comments/flced/what_are_the_best_episodes_or_seasons_of_nova_to/


 Nova episode