I use the built-in OSX "Keychain" app. It's integrated into the OS such that if you use the "save password" feature of your browser, it ends up in the Keychain

I use the built-in OSX "Keychain" app. It's integrated into the OS such that if you use the "save password" feature of your browser, it ends up in the Keychain anyway. It also generates great passwords, so now I generate a new pw for each site rather than re-using a handful of common ones.