A few years ago I got tired of getting back DVDs from unhappy customers so I went on a mission to find the most reliable combination of blank, burner, bit rate etc. I bought every brand of DVD blank available, several different brands of DVD players including very low end, used (from flea market) and new mid range units. I also borrowed a few laptops.
Here's what I found:
Use Taiyo Yuden blanks - DVD-R white printable surface, 8X write speed, but burn them at 6X speed.
Pioneer and Plexor burners created the most reliable DVDs
DO NOT use paper or other stick-on labels
Use Variable bit rate (2 pass is better than one pass, but they both seemed equally reliable) and set a maximum compression bit rate of 8 megabits/sec and the average of 7. This should be regarded as a maximum. There is only a very slight degradation of fast motion scenes if you reduce the max rate to 7 Mb/sec and the average to 6. The lower rates are friendlier to PCs, especially laptops, which may not have very good media player software.
I found no difference in reliability between Roxio and Adobe Encore software. I did have some trouble with freebie software downloaded from the net. Sorry, I don't remember the names.
Following the above guidelines I went from about an 8-10% failure rate down to only one reject out of the last approximately 300 burned DVDs.