If you are a conventional users (i.e.: only uses 700MB or lower cd's which are from reputed manufacturers) then go for the Samsung SM-348B or SM-352B. I own the 348B and they are not very eager to work with 99Min cds or other unknown brands. Media compatibility is still an issue with them but it should be mentioned Samsung ODD team is trying to solve this by continuously releasing firmware updates.
Can somone comment about the Writing aspect of Liteon or LG combos? There is a belief that hence Combos are dual headed they are not usually able write efficiently as their Writer only counterparts.