Tempest

Just add certain numbers to the end of your already existing password. It will make it easier to remember and stops the bots that just check if the same password is used in all websites, when a leak happens.

Well if it leaks again, I still just have to change it all; I'm just doing a unique password for each site.

Let me rephraze: Make different passwords by using your already existing one as the basis. If for example it was "Tempest", you can have the following used in different sites "Tempest01", "Tempest02A" etc