I began using Sony DVD-R disks, after switching from Tayio Yuden disks, as they were more cost effective. Tayio Yuden disks are renowned as probably the best disks on the market, however they do come at a price. I saw the Sony DVD-R disks on offer on Play.com some time ago, so I decided to buy some as it worked out quite a bit cheaper than the Taiyo Yuden.
Since the disks were on offer, I was expecting to find them to be of sub-standard quality, despite the brand name. However, the quality of the Sony disks I must say is second to none. I have not turned back since buying my first lot, and I can barely remember the last disk that failed on me. I would say that I have had about a 99% success rate with all the Sony disks that I have burned, about the same as the Tayio Yuden, but at a fraction of the cost.
I have tried many different branded disks over the years, and Sony are definitely the best that I have used, from a quality and cost point of view. A common problem with many other brands is that they will only play movies on certain makes of DVD players, but the Sony disks have played on several different DVD players for me without fail.
The Sony DVD-R can hold up to 4.7Gb of information, which is standard, and are of a 'write once' capability. The disks can store video, audio and multimedia files of any kind, and can burn up to a maximum of 4x speed, although there are also disks available that burn up to 8x & 16x speed.
If you want high quality DVD-R disks for all your multimedia purposes, then I would highly recommend Sony.