Definitely a regular login/password using my email address as the username and no validation on the password. I hate when I have to come up with a unique, really complex password for a site I don't use often unless it's a financial site or something.

Whenever I log in with Twitter or Facebook I'm always afraid that whatever I do on that site will be published to my Facebook or Twitter status.

My Google password is unique and precious and I don't want to use it log in to anything but Google.