I allways use Imation for both CD & DVD discs.
That was from a reccomendation on here that I started to use them. Used to use Phillips cdr's but had a few problems with them, so started using Imation.
When I bought this PC (my firstwith a dvd rewriter) I just carried on with them. Not the cheepest but never had a dud one yet (you watch, I'll get one now). I usually get them from Argos, 25 for £24.99.