I have been very happy with Verbatim General use DVD-R
I have tried a few others, and Verbatim seems to be the most durable
and plays in the vast majority of standalone or computer based drives.
TDK works very well for me - I have some problems with Memorex disks a year ago and made the switch - the best disks are Pioneer. They charge too much, so I don't use them that often. I bought 100 Optodisc DVDs for a buck a piece, worthless - don't waste your money on that brand!
Ritek (actually Meritline in this case) 4x DVDs have worked great with my Pioneer A05. They seem to play on everything that will play DVD-Rs (knock wood). ;)