From what I've learned during my own searches for the best drives for my builds, here's the deal with optical drives:
Many aspects of their performance -- particularly read and burn quality -- are extremely dependent on the media (discs) being used. Read the test reports on CDFreaks.com and CDRlabs.com and you'll see what I mean. Most drives out there perform horribly with certain brands & batches of discs, while their results with other brands/batches can be stellar. The variations in C1 errors (burning CDs) and PI & PIF errors (burning DVDs) can be huge, depending on what discs are used.
Because of this, it's impossible to say which brand of drives are "best." Also, as with many other computer components, you find yourself prioritizing and compromising. One drive might burn really fast, and really well, with certain media, but its tray might be flimsy or the drive might be really noisy (for example). So what's more important to you? Another might have a solid tray and be well-built, but might only produce really high quality burns with only a couple different brands of media ... or it might give great disc reading performance but have weaknesses burning discs (or vice-versa) ... or maybe its audio extraction is good but its seek times are slow compared to comparably-priced drives ... or maybe a given drive offers bitsetting with, say, DVD+R (which is a nice feature to have) but it lacks in other areas. You get the picture.
As for reliability, who really knows? Pioneer and NEC seem to have good reputations for reliability, and Plextor used to, but most of what we all get in that area is anecdotal, right? Like a lot of products, my guess is that reliability is more model-specific than brand-specific -- i.e., most of these companies prolly make some clunkers but also some really good drives.
IMHO, the best way to go about choosing a drive is to read the reviews on CDFreaks and CDRLabs and try to find the specific drive (rather than a brand) that's the best match for your priorities. Then buy & use the media that performed well in their tests, and you should be good to go.