If that doesn't work you are going to want to send it a data recovery company.
I am not a fan of Drive Savers but other companies that have a lot of experience and rep are:
Do not intialize the disk. That is going to really screw up the drive and make recovery more difficult. Also, check to see if the drive is making any kind of strange noises. Is it chirp or clicking? Does it make any rhythmic sounds? What happened prior to...