I used to use Datawrite Grey -R 8x (Prodisc F02 Dye) but I can't get them anywhere (Well I can but no guarantees on getting them with the Prodisc dye, more likely to get CMC MAG AE1 which are horrendous

)
I now use Taiyo Yuden -R (TYG 02 (8x) Dye) and they are absolutely fantastic, more expensive than the DataWrites but they work great.