Firefox does it for passwords if you pick to save your password but other fields I just have to double click the field and it drops down with a list of things I have put in it before.
Firefox seems to save passwords per domain name. This may not be specific enough in certain cases. E.g., if I have a password on domain.com, but domain.com offers web hosting at domain.com/username, then my understanding is it would be relatively easy to obtain my credentials for domain.com with the right phishing site at domain.com/username. Correct me if I'm wrong.
I can think of one site I had to use recently for event registration which suffered from the flaw I mentioned. (Note that I have no choice over which service to use here, as I don't run the event.) The site puts each event under different directories, not subdomains as it should. Firefox saved my login details for one past event and wanted to use them for another event. I don't know the extent by which the event pages can be customized, but if you could put the right JS on one event page then it seems there are multiple approaches to getting credentials and potentially obtaining sensitive information. Fortunately in this case an attacker wouldn't obtain much of value best I can tell.