Does anyone here in the forums have any experience with Data Recovery from a failed hard drive?

I have 230gigs I need to recover if possible from an external data drive.

I'm in deep on this one. It failed just prior to my getting it backed up. I did get some of my data backed up, but then kaput! It has many years of client files and personal files I would really hate to loose.

What about software to recover the data - Does anyone have any recommendations with software they've actually used?

Thanks for any advise you might have!