Is there any hope of recovering any data off DVDs which appear to be completely knackered?

I've just been going through some old disks to try and back up the data on them. Non are hugely important, but I'd rather not loose anything if possible. I have a DVD-R which no drive will accept. One drive spits it out, so I dug out the £600* DVD-RW drive which made the disk in the first place, 11 years ago, and that refuses to read it as well.

I did try the disk out in 2006/2007 and only some of the data was readable back then. I guess I should have tried to recover most of the data back then. Fortunately, I did save some of the data back then, but not all of it.

RetroSteve

*http://www.theregister.co.uk/2001/07/26/pioneer_dvra03/