[Pseudoscience-is-malarkey (OP)]

What is everyone's opinion on the most fascinating and/or important accomplishment of NASA's Cassini–Huygens probe?

[evan_au]

First landing on a moon (as distinct from landing on the Moon, which is a much easier proposition).

[chris]

The plumes on Enceladus that led to the discovery of a subsurface liquid ocean which might be a home for life. That was the winner for me.

This is a nice retrospective perspective on Cassini-Huygens' achievements by mission scientist John Zarnecki, who was on the programme recently.

[chiralSPO]

Yes, I would say that the info gathered from the plumes of Enceladus and the landing on Titan are my first and second choices for most scientifically important. I would also add that the photographs it took may ultimately serve science most, as they have inspired a whole new generation of explorers and garnered much public interest. NASA has an amazing photo gallery from the Cassini-Huygens mission https://www.nasa.gov/mission_pages/cassini/images/index.html and https://saturn.jpl.nasa.gov/resources/7786/ (they have many other galleries, for their many other missions... I highly recommend checking out the Dawn Mission for pix of Ceres https://www.nasa.gov/mission_pages/dawn/images/index.html, and Juno for pix of Jupiter https://www.nasa.gov/mission_pages/juno/images/index.html )

[Tomassci]

For me, it's a bunch of things.
1.images:They showed us the beauty of Saturn.
2.Titan landing: it may be liiiifeee! It may not. And that we landed on a extraterrestial moon.
3. That inspiration.
4. Enceladus looking good.
I don't know what else.

[Ophiolite]

While I understand the thinking behind the question, singling out any one aspect of the mission misses, perhaps, its overall importance. Here was a vastly complex mission (technically, scientifically, politically, financially, adminstratively), extending from concept to completion over decades, that was an enormous success. An adventure, a mission of discovery, a probe into the unknown, and it worked. In so doing it broadened and deepened our knowledge of Saturn's environs by orders of magnitude. Everyone of the points mentioned by other members, and scores more besides, are part of that remarkable achievement.