One of the biggest pains when signing up for a service or an overzealous policy is choosing a password. Back in the day, you came up with something you could remember. That was it. Then it became more complicated. Systems began requiring a mix of upper, lower characters, special characters, and numbers. Soon our passwords looked something like P@ssword123. Then with being forced, usually at work, to change them periodically, we soon just settled into P@ssword1234, P@ssword1235, and so on and so on.
Enter Hive Systems and their "Password Table" that explains how secure a password can be. They recently updated it based on the newer processing power inside graphics cards and the ability to purchase very-powerful cloud computing to help crack a password.
So, complex 8-character passwords that once took 8 hours to crack now only take 5 hours!Hive Systems
The site is very technical, but I'll show their table below with the results. Bottom line: any password you pick that's 13 upper and lowercase characters in lenth is very secure.
Bottom bottom line: Use one of the many password managers out there to generate a unique password for every site you use, and save yourself the trouble of creating & remembering all these passwords yourself.