I've found Falstad very easy to use and intuitive. With also a lot of examples and common packages.

Are there modern, with more features, example and packages, like Falstad?

But what I'm looking for is grapically intuitive to use and very fast to setup (to test if circuits are ok).

Any advices? Free and commercial are ok.

 

Hello,

You will see that LTspice is used here by many users.
https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html
https://en.wikipedia.org/wiki/LTspice

It will have a steap learning curve, but is very powerfull.
There are a lot of examples delivered with the software package.

Bertus