I'm looking for the same thing. Debating between a dvd-rom vs a combo drive. Lately I'm leaning towards a dvd-rom only. Liteon's and Sony are the same drives now. I used to like liteon's but they're too noisy for me now. Regarding ability to read bad discs, I've heard just the opposite regarding Liteon's.
I've heard in these forums that the AOpen 1648 is a very good reader/ripper AND QUIET so I probably will get one of these.