This is a hard question for me.
I don’t have much experience with various RPGs so I don’t have many to compare. However, I’m very pleased with the writing of everyone I’ve tried. But since I don’t want to answer with D&D 5th edition again, I’m going to go with Star Wars RPG by Fantasy Flight Games.
I don’t own any of the core books, only the Star Wars: The Force Awakens Beginner Game. I found the writing exceptional. It was written in a way that made it very easy to understand the system and how to run games with it. With almost zero prep I managed to successfully run the introductory adventure, while also teaching the system to my players.
And that’s my answer to today’s question. It’s a very interesting question so I’d love to hear your thoughts.
Tomorrow’s question is “What is the best source for out-of-print RPGs?”.
So until then, have fun!