Lastpass. They store everyone's data online, but it is encrypted on the client side. You can't just hack into their datacenter and get people's passwords.
The only way someone can see your passwords from their end is if they get your master password (should you choose to use that scheme). You can use a really strong master password, meaning randomized, alphanumeric, >=12 chars to protect against brute-force.
The downside, at least for firefox, is that it's been bogging it down lately, but I have a lot of extensions running, too.