Consider whether any of those associated sites are still useful. You can enumerate these on Facebook itself, it shows you which sites have access to your account.

Secondly, make a list of these sites. Ask yourself: "if I lost access to these sites today, would I care?" - remove the ones you don't care about.

Lastly, separate each one from Facebook one-by-one. Some will be easy, log-in, set a password, unlink Facebook. Done. Some will probably require getting in contact with the site's support team.

Don't worry about doing this over night. Just rest in the knowledge that every step you take, is getting a bit more control over your data.

Eventually the list will shrink, and then you can start the mammoth task of doing the same things with:

* Your post history

* Your likes

* Your check-ins

* Your reviews

* Your event history

* Your employment history

* Your photos

* Your wall posts

* etc.

Good luck!

If you go to https://www.facebook.com/settings?tab=applications you can see a list of everything you've signed up for using Facebook OAuth, then determine from there what sites you still use and adjust logins as necessary

Keep deleting it after you enable it to login to whatever site and the delete it again after you changed your credentials on said site. Eventually it will stay deleted/disabled and lost at some point.

Thats what I did and the Facebook account is gone now. Haven't encountered any problems so far.