I use the one built into Firefox. Probably not a good fit for your situation, but it's saved my bacon at least once: I started to enter my credentials on a site

I use the one built into Firefox. Probably not a good fit for your situation, but it's saved my bacon at least once: I started to enter my credentials on a site and then thought "wait, why didn't Firefox auto-fill my credentials here?" Then I noticed the domain didn't match the rest of the site.