Holy [r@p! How will I remember a password that has 20 characters from all classes!
You could do what I do, use a long sentence of words smashed together. The more non sensical the better. To add to the difficulty, mispell the words, incorportate a long number, alternate cases and use non alphanumerics, the use emoticons is a bonus, especially mid sentence.
For example :
whee2731}
Original
We 2731 }
Both are not too hard to remember and pretty insane to guess unless you are god
I use a very long insane password on very very sensitive, log in once per week accounts. I don't even allow network logins, only console, but I'm paranoids about all aspect of security. Though, users are by far the weakest link, you have to protect them against themselves.