Something to keep in mind is that security isn't just about preventing attackers from accessing it. If that was the only criteria, then the most secure thing would be a flash drive buried in concrete.
Security is also about accessibility.
To that point, I believe the best password manager is subjective. That being said, I'm going to throw out a recommendation for 1Password. If you use it right, it balances security with convenience really well.
I have been using 1Password for a few years now, coming from LastPass before the whole bait-and-switch thing they did. I love 1Password, but I am curious how it stacks up to BitWarden since everyone in this thread keeps mentioning them.