lx6g

You can choose from upper and lower letters, digits and special characters to make your new hardcore passwords impossible to break. 
And yes, all the passwords are generated only within client’s browser session and are not saved anywhere on the server side, 
so it is absolutely safe to use in real world.
You can also specify the following attributes to tune the form’s appearance:
<ul>
<li><code>length=4..64</code> specifies the default length of a password. Allowed values range from 4 to 64. </li>
<li><code>upper=1</code> enables upper-case letters option. Activated by default.</li>
<li><code>lower=1</code> enables lower-case letters option. Activated by default.</li>
<li><code>digits=1</code> enables digits option. Activated by default.</li>
<li><code>special=1</code> enables special characters <code>,.:;_=</code> option. Disabled by default. </li>
</ul>
Plugin’s Official Site
<a href="http://lx6g.com" rel="nofollow ugc">Alex Granovsky Blog</a>

LX Password Generator

LX Password Generator is simple yet nifty password generation form to be placed in any page or post you like.

Outerbridge

Password Generator is a plugin written by Outerbridge which adds a widget to WordPress which generates various length random passwords (with or without special characters).

Password Generator

Password Generator is a plugin which adds a widget to WordPress which generates various length random passwords (with or without special characters).

LX Password Generator vs Password Generator