Here’s a great list of the top 500 worst (most commonly used) passwords.
The Top 500 Worst Passwords of All Time

It’s another great reason why I use 1Password.
One of it’s best features is the Password Generator.

For any site or service I sign up for I use the Password Generator to create something nice and random. 1Password then remembers it all for me. So I only remember my “1 Password” and 1Password remembers the rest.
I thoroughly recommend it. It’s integration in to all major browsers is fantastic.