Rated 5 out of 5 stars
If there's a downside to Lastpass, it's the fact that it gives you so much power to organise, manage and secure your passwords, it can take a while to get used to it. But in my view it's the single most important addon that any user with security concerns -- and that should be EVERY user, right? -- can install. It's under continuous and active development (so it just goes on getting better at what it does) the developers clearly care deeply about making it do everything its users need (and probably odd things they haven't thought of yet) and it's one of the two must-have addons I tell everyone about.
If you have perfect recall for all your secure passwords, you don't need this. For everyone else, nothing else I've ever used is as good as LastPass.