There’s a good password generator embedded into Google Chrome. It appear when you create a login in the “input type password” fields.
But, if you need to generate a password for something else, e.g. mysql database user, there’s no way I found to use it from the menu or somewhere else.
That’s why I create that “fake” signup form, just to use the “generate password” chrome feature.
Save it in in your bookmarks and enjoy!