Some of the DVD drives are known to have more issues than others -- for example, the early Thompson drives are FUBAR and are worse than the Samsung SDG-605 -006 drive, which is regarded to be worse than the -005 version. This is the main drive known to die, besides the -006 SDG-605 on “as-is DRE” consoles. The Samsung drives try and compete with Thompson on failure rate at times.
For the good but easy to find ones (with some issues), the Phillips are a good balancing act option. They still have issues, but not as good as the Hiatchi drive -- but also, less failure prone then Thompson or Samsung.
Hitatchi is the unicorn drive you want, but it will remind your wallet. Super rare, if you get it cheap shut up and pay. Even better if you get a used console and it comes with it; keep your mouth shut once you can tell.
Refer to this guide to replace the drive, and see which one you have
Bearing a guess based on the manufacture date (which will clue you in on the revision, which can be a starting point), the best way to confirm which one you have is the design of the tray.
Of all the drives you can buy, AVOID THE THOMPSON! Those are known to be unreliable, and also drop like flies! You can abandon them for a better one with the original Xbox.
In some cases, the drives can be saved by cleaning the lenses, but that's usually not a long-term solution; but it might buy you a little more time before you have no choice. That said, entire replacement drives aren't cheap so you'll either need a donor unit or wait until you can get one at a reasonable price, unless you can replace the laser and get the drive working — if you can find it, as each drive uses a different laser.
If you can’t find a drive, sometimes you can replace the bare laser if you can find a match. For Samsung, it’s easy but you cannot put a -005 laser in a -006, or vice versa. Phillps drives do not die regularly, so it’s not as common as you do not need them as often.
Thompson lasers are not worth your time — often trimpot fixed to their demise due to the notoriously bad failure rate alone, which often screws the next buyer over if a novice did it. DO NOT FIX THESE — DUMP THE DRIVE BACK ON EBAY FOR PARTS.
My repaired console had the SDG-605 which has trouble with CD-Rs (X00603-006), and I installed a Phillips drive (AD0365/21)* as my PCB is dead, and I couldn’t find anything else at the time. I scored the drive for $40**, so I got a once in a lifetime deal on the part. It took 14 months to do it, but I fixed it despite the cost because I got mine from someone who gave me a serious lead to where I am who passed away, so the Xbox has sentimental value. It took me a bit to do, but I was willing to see the repair through in hindsight after he passed.
*At the time, I got what I could as long as it wasn’t a -006 SDG-605, or a Thompson. I didn’t know my drive was so good at the time of purchase, and how well I did for $40.
**I did it in 2020.
The optical disc reader