They may have existed at one time. I doubt those tapes still exist. And really, who gives a shit about Clinton or Branson in the grand scheme of things? Branson isn't a politician so only he will suffer and Clinton has always been a philandering dog. No sex tape is going to make his reputation any better or worse.
Prince Andrew, however, would be well and truly finished were such a tape to come out and be verified. It would be concrete proof that he lied and this time it wouldn't just be his royal titles that would be removed. He'd be cut off completely. No more cash. No nothing. He'd have to sell his story to the Daily Mirror just to pay the rent.