Personally I would choose NEC as that's the brand I have the longest experience with and my old 2500A is still working. I currently have a BenQ 1640, crossflashed from a Philips 1628, and it's doing it's job too, but I have only had this PC a few months so not enough time for me to decide fully.
BenQ and NEC are pretty good makers of writers. If you are not interested in scanning go for the NEC as it doesn't do the full scanning that BenQ can do. The is one downside to NEC writers and that is they are not that good a reader, so a disc may be unreadable in an NEC but readable in a ROM or BenQ writer. If you have a seperate DVD-ROM this is not too much of a consideration for you.