What is the best self-defense system?
No one best system, all have their merits. And some systems will have conflicting philosophies to the same problem or attack. Just make sure the system is geared to what is likely to happen in your environment or reality, and trust your intuition on the best ‘fit’ to your temperament. If you want to go deeper, you may even want to learn more than one system to complement for weaknesses of another.