Remember one password; have secure passwords for every website.
Password managers allow you to keep a digital vault of passwords that are uniquely and randomly generated for every secure site you login to. In addition, the password manager will automatically fill the password in when you visit a site on your computer, so you don't have to remember the complex password it generates.
The end result is a randomly generated complex and unique password for every site you visit, that gets automatically filled in for you, so you don't need to remember. This increases the security of your digital services. In the event one account is compromised, the remaining passwords stored in the vault remain secure; by hacking one service, hackers cannot get in to all of your accounts.
There are many providers this type of service, but we recommend LastPass for best results.