Ron Bowes did an analysis of the rockyou.com passwords to see what the number of accounts you would nab with the top X number of passwords. This shows how a bigger password list has diminishing returns.
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He has made the top X password dictionary files and other password lists available in his wiki at http://www.skullsecurity.org/wiki/index.php/Passwords. I you want more details you can read the whole article at http://www.skullsecurity.org/blog/?p=516
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He has made the top X password dictionary files and other password lists available in his wiki at http://www.skullsecurity.org/wiki/index.php/Passwords. I you want more details you can read the whole article at http://www.skullsecurity.org/blog/?p=516