if u r choosing for dvd writers then i suggest that u go for a sony or a liteon .. they're the best dvd writers available in the market ... i myself bought a sony dw-g120a writer a few days back n its working smoothly ... dont go for samsung optical drives .. they dont last long
I am also using DRU-820A, it's working perfectly, has DVD-RAM support and writes quite fast too. It cost me 2.8k here, I bought the original box packed one. Someone mentioned here that it os nothing but a Benq DW 1670, one of the best in the world.