A SQL Server installation requires a lot of service accounts - and then a lot of secure passwords.
I have tried various solutions, and for now I am using PC Tools Secure Password Generator on the web. It works nice, and is secured by HTTPs communication.
I still have to store the passwords in a secure and yet available place. The old school solution using paper, envelopes and a solid safe still works in some degree in smaller organisations.
In a larger organisation, or if availability with a audit is required, I have for some time used thycotic Secret Server in a local installation. It requires a software installation - with a SQL Server database, but it is secure and easy to use.