Don't use the built in password storage of any browser. Doing so leaves you vulernable to bugs such as this one: http://forum.avast.com/index.php?topic=25044.0;wap2. I.e., if a hole that leaks passwords exists, your browser could be leaking all your "high quality" passwords without your knowledge.
Instead, do as michiel3 suggests. Use a separate, independent, password manager. There are plenty out there. I recommend (and use) Password Gorilla myself (https://github.com/zdia/gorilla/wiki).
This way, your passwords are protected from browser bugs (should they appear). Further you can easily make completely independent, strong, passwords for every site, because you are not remembering each, you only need remember the unlock password(phrase) (hopefully also strong) for your password manager app.
Instead, do as michiel3 suggests. Use a separate, independent, password manager. There are plenty out there. I recommend (and use) Password Gorilla myself (https://github.com/zdia/gorilla/wiki).
This way, your passwords are protected from browser bugs (should they appear). Further you can easily make completely independent, strong, passwords for every site, because you are not remembering each, you only need remember the unlock password(phrase) (hopefully also strong) for your password manager app.