Are you looking for a DVD-ROM or a DVD-RW?
Traditionally I liked LiteOn for many things. It is rumoured to be the best reader, it is cheap and as a drive, it does what you tell it to do (it won't be like "what you ask from me to do is illegal & therefore I don't do it. If it can do it, it will do it). And there is no moaning about people moddifying their firmwares like it is with NEC.
I've owned the last 2 DVD-ROM drives from Lite On (167T & 16P9S). I don't have any complains from either of them. The second is better for disc quality scanning. Speed-wise they both read at only 8x for recorded SL media, but there are modified firmwares available to unlock at whatever speed pleases you. In practice, they can read quality-burned SL media at 16x and DL at 12x without problems.
Oh BTW, there is no rip lock in Lite-On drives. The official firmware understands when you want to rip & rips full speed and when you watch a movie, it slows down. You patch the firmware only to increase the recorder media reading speed.
http://codeguys.rpc1.org/ (the site is overloaded half of the times)