Frankly, I don't trust password managers. Perhaps I'm naive and they're perfectly safe, but still.
My solution is to develop an algorithm for all my passwords that is pretty quick and simple to memorize but allows me to "generate" a unique password for each service that I use.
Although I seriously doubt anyone could figure out my algorithm by learning one of my passwords, I'll admit that if they were to gather 3 or more then they'll probably be able to figure out my system. But since I never write down or record any passwords whatsoever (all I need to remember is my algorithm), someone would have to steal my credentials from multilple sources and also be able to know which credentials from one service match a user from another, etc.