Like many others, my favorite knot hands down would be the Palomar Knot. It's easy to tie, suitable for both terminal tackle and the drop shot, and works well across different line types. It's even a top 10 knot in terms of knot strength, as per
https://www.knotsforfishing.com/knot-strength-chart/
Uni-to-uni for leaders.
Improved clinch knot for teaching beginners.