After getting its license from the CySec (Cyprus), Banc de Binary has now also a FSA (Financial Service Authority) registration in the United Kingdom. It is the only binary options broker regulated or registered in these two countries.
So if you are looking for regulated binary options, you should choose Banc de Binary. At this time no other binary options broker is regulated.
Banc de Binary is also working on getting a license in the US. Until they get it, they do not accept traders from the United States.
Remember that binary options regulation is only starting, so other brokers should follow and get their licenses too.