Check out the Simple Strong Password Generator website.

UPDATE:  If the Simple Strong Password Generator website isn’t available you might want to try MakeAGoodPassword.com or the XKCD Password Generator from Preshing.com.

There’s a link on the page explaining why four simple lower-case words is more secure than a shorter, harder to remember one with lots of upper case letters, numbers, and “special” characters.  (Tip: for most modern systems like Google, Facebook, WordPress, and the like a spacebar is a special character anyway.)

Simple Strong Password Generator website screenshot

Tip: The password in the image above is just an example — don’t use it for your own password because it won’t be random.  Instead just click the link and a new password suggestion will be waiting for you.  Don’t like the first one?  Refresh that page and it’ll give you a new one.