This article is from the CD-Recordable FAQ, by Andy McFadden (firstname.lastname@example.org) with numerous contributions by others.
CRX100E/CH (24x4x2/1MB;IDE) and CRX100E/X (6x4x2/1MB;USB)
CRXP-90MU (24x24x10/8MB;USB2.0, also reads DVDx8, portable)
CRX1600L "i.LINK" (32x12x8/4MB;FireWire)
CRX175A/A1 (40x24x10/2MB;IDE, /A2 is USB)
DRX120A (32x12x10/2MB;IDE, DRX120L is ext. FireWire, also writes DVD+R/RW)
DRU128A (32x12x10/2MB;IDE, also writes DVD+R/RW)
DRU500A (32x24x10/8MB;IDE, also writes DVD+R/RW and DVD-R/RW)
DRU510A (32x16x8/8MB;IDE, also writes DVD+R/RW and DVD-R/RW; UL is USB2.0)
CRX195A1 (48x40x12/2MB;IDE, CRX1950U is external USB2.0)
CRX210A1 (48x48x12/2MB;IDE, CRX2100U is external USB2.0)
MPD-AP20U (24x24x10/?MB;USB2.0/1.1, also reads DVDx8 and plays DVD to TV)
CRX300A (48x48x24/2MB;IDE, reads DVDx16)
CRX320A/U (52x52x32/2MB;IDE, reads DVDx16)
[ There are also a number of DVD recorders that also record CD-R/RW ]
The CDW-900E has a separate connector that allows multiple "slave" drives
to be daisy-chained, allowing multiple CD-Rs to be written in parallel.
The Spressa 9211 is a 920 in an external case, the 9411 is a 940 in an
external case, and the 9611 is a 926. The 940S drive is actually a 924S;
the 940S designation refers to the complete bundle (software, cables, etc).
Looks like each unit can be referenced by three different numbers.
Some people have criticized the CRX100E for being unable to write more than
about 78 minutes on an oversized (e.g. 80-minute) blank, and being unable
to "overburn" a disc without resorting to swap tricks. It appears that
firmware v1.0n removes this limitation.
Some older Sony drives have a special "recover" feature, accessible from
programs like Easy-CD Pro '95. This allows recovery of the CD-R media
after certain classes of failed writes.
All Sony drives can do packet writing.
Firmware for some models can be hard to find.
CAVEAT EMPTOR - CDU926 and CDU928. Believe it or not, the CDU926 and
CDU928 don't support disc-at-once recording (see section (2-9) for a
description). Instead they use "variable-gap track-at-once", which allows
TAO audio recordings with barely perceptible gaps between tracks. Some
popular software packages aren't as useful when disc-at-once isn't
available, so people considering these drives should carefully consider how
they plan to use them.
(All other Sony units do support DAO.)