Hmm... Well, Blu-ray Discs are inorganic (copper and silicone if I remember correctly), so it would seem to me, that under optimal circumstances, they would last even longer than either CD or DVD. Amazing... I didn't know Flash drives would last THAT long... Now if only there was a way to write-protect them... That's the thing I like about DVD+R; you can't erase it... But, the organic thing is a problem...
All of my CDs, save for one, still work, and I've had some of those for 10 years; some of my backups are AT LEAST 5 years old. However, to be on the safe side, I have made backups of some of the lower quality CDs... (I don't really intend to burn to double layer, either... If you burn data onto a single layer DVD, and it goes bad, you'd only lose about, maximum, 4.7GB. However, you'd lose DOUBLE that if a double layer DVD was to go bad...!!! Not good...
I forgot to mention, that the CD that I had problems with, was a CD with a bunch of .WAV files; I was able to extract all the files with ISOBuster, and reconstruct them to be usable again, cutting out the "bad parts" that were left behind. (The disc had minor label damage. Peeling/flaking...) Fortunate thing that it was only a bunch of .WAV files, and that the majority of them - especially ones that were semi-important to me - were mostly untouched...
EDIT: Oh, and for the record, I have ONE Flash drive, a 1GB Memorex, intended to be used mainly for my college stuff. When college fell apart, I was left with a way to transfer files without opening my computers and swapping hard drives...
"And the Most High said unto Moses, Ahayah-Asher-Ahayah. And he said, Thus shalt thou say to the children of Israel, Ahayah hath sent me unto you... This is my name forever, and this is my memorial unto all generations."
1953-2011... One day, mother, I shall see you again...