O26: DVD-R of choice.
When you're making home-grown video DVDs, you have to choose between two formats and several brands of recordable media.
The format decision, whether to use DVD-R ("DVD dash R") or DVD+R ("DVD plus R"), is easy: DVD-R all the way, as that format has been around longer and is, therefore, compatible with more older DVD players. Do note, though, that some (usually really old) DVD players can't play back any recordable media.
As for which brand of DVD-R, I've had the most luck with Verbatim discs. Compared to other brands, I've found them less prone to errors during the recording process and more compatible with various makes and models of set-top DVD players. And I know Jimbo agrees with me on this one, so that's two votes for Verbatim.
(In a pinch, Maxell DVD-Rs are my second choice.)