mail.google.com to deal with the legacy of a world full of email.
facebook.com to stay in touch with people from my youth, for various values of youth.
twitter.com for news, and to pay attention when there's a thunderstorm.
plus.google.com for that new software smell; not certain what's there yet, except that there's a lot of it, and that the social conventions have not yet ossified to the point where anything is predictable.
typepad.com/dashboard because at some point you need to not be following everyone else, but instead be following yourself, and it's always easier to follow yourself when you have an empty screen with a cursor to type into and no idea on earth who is expected to read it.