Remember, organizations get hacked all the time. Having one password for all your logins is dangerous. At a minimum you should have 5 passwords: 1-High Security (banking), 2 – High (shopping), 3 – Low (forums and groups) 4 – Work and 5 – Personal Email
Never use passwords that someone could guess from you. Common gotchas: Your kids names, your pet names, your job, your hobby… Just to name a few. Oh and NEVER use a dictionary word.
Or the common password: password, 123456, 12345678, abc123, qwerty, monkey, letmein, dragon, 11111111, baseball (as of 2012)
If you can, use a password management program like 1password, roboform, etc.