Sorry to hear that. I've recovered files with R-Studio and GetDataBack (though GDB lets me down sometimes). But what saved my tail on one dead drive was SpinRite 6. I've heard many sad tales which have ended happily thanks to letting SpinRite run on your drive for DAYS on end.

SpinRite is a boot disk with FreeDOS and an app which accesses the drive at a very low level. It makes the drive recover data from sectors that it would usually ignore as "bad". It can test read/write ability, refresh every sector, and all sorts of things. Most interestingly, if it hits a bad spot, it may invoke statistical analysis to estimate what each bit may be. It apparently re-reads a sector up to hundreds of times, positioning the read head slightly different each time to get a different view on things. With enough data, it can estimate. And if it guesses wrong, maybe you end up with a few flipped pixels in your image.

The mind numbing part is, SpinRite needs to run for DAYS, maybe even a week on large drives. If your drive is not clicking to death, let it run. From personal experience and what I've heard from others, it will really help.

An important tip: Run SpinRite on the disk in the machine it was always in, from the same IDE header it was on, set as Master if it was. Everything the same as it's been running for years. I transplanted my dying drive to another machine and it SpinRite locked every few hours. Back in the machine it was for years, SpinRite ran for maybe 3.5 days before I finally stopped it.

Possible causes of your corruption: I've recently had two drive semi-failures like you. Both were power related. One machine was plugged directly into the wall during a power outage. It booted but didn't load some startup items, so I rebooted and it was hosed. Running chkdsk probably made it worse. The other drive was one of three in a case probably underpowered by a cheap power supply. It clicked off during use (not the first time) but didn't click back on (like it had in the past). I was able to view it as slave, but only with great patience as it occasionally got stuck while reading for minutes. Got almost all 10 gig off it in one long day.

Good luck. SpinRite!