There is no such thing as best, it depends on what your perceived need are, as well as the operating system you are using. If you are going to do a PCB, then some idea of what your requirements are would help. Additionally, you may quickly outgrow a low end package, so it helps to have some idea of where you may be headed in the future. The reason is quite simple, despite what all the vendors or suppliers say, there is always a learning curve, some are quite steep, so you have to invest quite a bit of time to learn how to best use whatever you choose. Secondly, there is a big investment in creating libraries, which are often not transferable to another package if you decide to change. It can therefore be worthwhile exploring that feature carefully when choosing a package, since some have extensive libraries, or have the ability to download them from web sites. Don't rely on the libraries to be accurate, you need to check the part against the data sheets to be sure on the first use.Cloud based packages need a good internet connection, and your design files may not be secure, which may have commercial implications.There is a link here which may be of some help,https://www.circuitsdiy.com/best-free-pcb-design-software-list/
I personally use PADs, a commercial package, that was a decision forced on me many years ago, I am now very familiar and comfortable with it, and have a vast library of parts and fixtures, like any package, it has its quirks and quite a learning curve. There is a free very limited addition available through DigiKey which is not in the list above, but it's not open source, so doesn't meet your criteria.
Cheers,Richard
