The Good, Bad and Ugly
Good: Secure passwords are long and complex making it difficult anyone else to use your ID and password.
Bad: The hardest to type and remember are the long and complex passwords.
Ugly: Always forgetting those good passwords, using a sticky note to post the passwords on your monitor, using simple insecure passwords, etc.
The Balancing Act
Personally I use Password Safe (http://passwordsafe.sourceforg
The best passwords are long easily remembered and use upper and lower case letters, numbers and symbols (including spaces). I usually take a phrase, misspell some of the words, use capital letters in odd places and add unusual punctuation. As an example (and don't use this):
DoC+doktor w3re gona kr4sh#
Butchered from the following phrase:
doctor doctor we are going to crash