Diceware is a great way to generate a strong passphrase without having to memorize a random set of characters and numbers.
Check out the EFF's page on diceware.
Typically passwords are made with actual dice and this is the preferred method.
However I made a small script to generate a diceware password.

You can check it out here.

You'll really only need curl. It would work fine with wget, you would just have to change the command to:

wget -q -O -