I use Ophcrack, Austrumi and L0phtCrack (yes, they're back on http://www.l0phtcrack.com/) but I just found an innovative password recovery tools:
It's innovative because it doesn't reset your old password or try to recovery from hash, it changes the kernel on the fly while booting to allow you to bypass the login password.
In Windows you can use a blank or garbage password, you will then be logged in as that user and can access all their files.
In Linux you will use the user name kon-usr and no password. This will give you full root access on the machine.
It's a small ISO you can burn into a Floppy or CD-ROM or USB.