I tend to receive faulty (for repair) or obsolete equipment from people, so I only bought some of these!
Yamaha CRW6416S 6X write 4X rewrite 16X read SCSI CD burner. Obsolete, worked last time I tried it.
Asus Cd burner, unknown model. Received dead, couldn’t be bothered trying to fix it
Plexwriter PX-W124TSi. SCSI CD burner. Received from scrapped computer, not tested, obsolete
Pioneer DVR-A06. Dead - not seen by BIOS. Haven’t gotten around to fixing it.
Optiarc AD-5170A. Stopped burning dual layer disks, then stopped burning single layer disks, then stopped reading disks, then stopped ejecting disks. Produced occasional coasters even when new and produced impressive amounts of noise but delayed failing until warranty had just expired. (Does RCM have the only AD-X17X drive on the planet that works?)
NEC ND-2500A (crossflashed to 2510 but unfortunately fails to burn DL). Not retired, merely resting. Was intended to be replaced by the Optiarc (which could burn DL and was faster), instead ended up replacing it. Never had a single failed (SL) burn. Currently disconnected since I now have a nifty Pioneer 216 and I needed the single IDE controller for an old disk. I’ll probably replace it with another SATA optical (mainly to avoid IDE cabling) at which point I’ll move it to another computer.
I’ve also thrown out various CD-ROM drives that where obsolete.