Master Password is a free website to generate strong passwords. Although there are lots of strong password generating websites and software already available, but this is a bit different and more secure. This website lets you create strong passwords using your name, master key, and website name (for which you want to create the strong password). Only the right combination can generate the same password again. Moreover, output password is not stored on servers and only you can access it or recreate it. Anyone who wants to access your account(s), he/she must know the password generated using your name, master key, and site name.
The web version of Master Password is in beta phase, but it worked pretty well during my testing. You can also use its smartphone apps, desktop or Mac client according to your requirement.