LGs have very good burn quality (if you feed it with good media). I would recommend the H22 (Panasonic) instead of the H42 (Renesas).
If you want accurate quality testing and/or a learning mode, you should get the LiteOn.
The ASUS is nothing special (except for being a three sheep burner) but for backuping data and movies it should not make a difference.
The Sony is a relabeled Samsung. Again, nothing special.