The very worst DVD media ever has to be that manufactured by Sky Media...
I stupidly bought a couple of 25-disk cakeboxes of their 4X -R disks and consequently lost A LOT of valuable personal data. All the initial burns were fine (verified OK, no coasters etc) but in spite of careful storage, within 3 months of writing ALL these disks were unreadable :a
Not an isolated incident from a single bad batch, either... exactly the same happend to other people
See my rant in the media forum for more details:
The company which produces them is based near me in Switzerland and sometimes tries to play the 'Swiss Quality' card, but don't believe it!
If you wonder why this company are so happy to churn-out the lowest-grade unfit-for-purpose crap imaginable then the following, supposedly 'promotional', article has a few interesting 'nuggets':
QUOTE: "Why then the plant is built in Switzerland, not in Russia? At first glance, the Siberia with its vast expanses, a convenient position between Europe and Asia, with quite cheap labor force and technically competent people, or not less attractive Kuban with its mild climate must have attracted a lot of European and Asian manufacturers.
The explanation is simple: the Russian government doesn't feel any desire to attract investments from the West. The SKY Media's plant was built with the help of the Swiss government that helped a lot in choosing the best place, training the staff and creating the tax policy favorable for the firm's development, because the government understands that the profit from such a deal is going to be big and soon."
AVOID, AVOID, AVOID!!!!