I use several tools depending on context (keepass for work accounts, a custom hosted solution for everything else). But I also have a system for my passwords that allows me to figure out what it should be in case I forget. Most of my passwords follow a specific pattern that incorporates the platform and a series of characters.

This specific implementation is now out of date, as it's not really necessary (or at least it shouldn't be) to have all the special characters; length should be the critical property of a secure password, but unfortunately many, many sites still require a mix of upper/lower/numbers/special chars. Regardless, it should still be simple to come up with a way for you to know your passwords, without them all being the same.