I use DVDRs since I can get a whole series (26 episodes) on a single disk...
I use TDK since my dvd drive is from them too... (well, it is really made by Pioneer and just rebranded to TDK...)
EDIT: Tho, I only burn series I wouldn't mind seeing again (which hasn't been released in the US yet...) but I haven't watch any of the series I burned on dvd yet...