Yeah, I agree with Ruffrob. I have spent many hours looking at various DVD media descriptions and reviews.
As far as I can tell there are mainly two tiers of DVD media: Quality & Crap.
Some can get by with noname (or Princo) type brands if they burn at 1x, but I look at it from the perspective that I want my data and movies/music to last a lifetime, and after seeing all the same issues with CD media, I will not go with any less than Ritek (which is at the bottom of the quality category).
I think the other decision is over DVD-R or +R if you have the Sony. I have used at least 25 of each media, and burned at speeds of 1x and 2x. I actually took 6 different media to my local electronics superstore that carried 8 or 9 different DVD player brands, and all 3 -R and other 3 of +R all played on every player.
I now see no reason to pay 3-4 times as much for 4x media when all it saves is 15 minutes to burn. I can personally vouch for these specific meritline.com links: Ritek-R (G-03 rated) $1.10 each & Ritek+RW $2.29 each.
I also know that Philips DVD+R DVD+RW works well, as does Verbatim & TDK