Verbatim DVD+R DL. Not a single return out of maybe 100, and I can burn them at 8x, making even a 7.95GB (full disk) burn bearable. Don't care much for the old-fashioned matte white inkjet surface, but Taiyo Yuden is probably not interested in letting Verbatim use their Watershield technology.
Doing hi def disks on regular dvd media really pushes the media to its extreme. I have had problems creating DL hd dvd's with everything EXCEPT Verbatim (I use the Verbatim DL inkjet printables)