I've used Recuva with great success in the few times I used it.
Story:
Ten years ago, I was caught taking pictures at a concert, where the Theater forbids all photography. Smith Opera House. Geneva, NY.
Head of Security wanted to confiscate my camera. I countered: "How about I format my card in my camera, right in front of you?" The dude agreed and I formatted the card while he watched. He then let me return to my seat with the camera, with me agreeing not to take anymore pictures or suffer instant ejection from the premises. Done.
Later that night, I used Recuva to pull all the pictures of that 'formatted' card. Bwahahahahaha!