Top recommended by WordPress experts

Very clear and easy to use.
Backup your WordPress database before using, of course!
Implement one element at a time, and test thoroughly, before implementing another. Several security features don’t work with all hosting account setups.
First one to implement should probably be to limit login attempts.
Several other plugins have a few of the features this one has; best to only have one (this one) handle a security feature, duplicates just make server work harder.