In my opinion theres only 2 different family of drives that I would consider buying.
One is the current gen NEC chipset drives, such as the Sony Optiarc AD-7240S or AD-7241S
you can check out a thorough review of the drive here
http://www.myce.com/...r-review-15981/The other is the current gen MTK chipset drives, such as the LiteOn iHAS124A or iHAS424 A
pretty much any iHASx24 A labeled drive where x is a number 1-8 (differnt number means different features such as lightscribe/smarterase etc.)
you can check out a review of the drive here
http://www.myce.com/...r-review-23899/Both of these drives are great dual layer burners. I would give the edge to the MTK chipset drives (the LiteOn) simply because you can do disk quality scans with it.
The down side is that LiteOn, is, for some reason, using both MTK and NEC chipsets. So it's actually impossible to tell which is a real LiteOn and which is a NEC rebadge if you're buying it online.
So if you end up going with a LiteOn you might instead get a LiteOn drive that is a rabadged Sony Optiarc AD-7240S drive, this isn't a bad thing, as it's a great drive none the less, but you could have simply bought the Sony Optiarc AD-7240S and saved a few bucks and gotten the best firmware support for the drive.
In conclusion I recomend you read the reviews
If you decide to go with the NEC chipset, get the Optiarc AD-7240S (unless you need/want lightscribe, if you do get the Sony Optiarc AD-7241S)
If you want to go with an MTK chipset, you will have to take a gamble. I bought an iHAS124 off newegg and got a real MTK chipset.
There are many more reviews and discussions on the site about current drives (as well as old ones that are no longer for sale) so browse through them. Though in my opinion, those two families above are the best ones out you can buy right now.