Formally in English there should only be "Yours sincerely" or "Yours faithfully". Note that sincerely never starts with a capital S or faithfully with a capital F.
If you begin a letter with Dear Sir/Madam, then it should be signed off with Yours faithfully. Everything else ie Dear Alan, or Dear Mr Jones, should be signed off with Yours sincerely.
If you are writing an informal letter to a friend then you can pretty much sign it off with whatever you like ie yours truly, kind regards or whatever.