-listslots is very useful. Man, that list is impressive. So many cool things to try.

aesms Applied Engineering Super Music Synthesizer
aevm80 Applied Engineering Viewmaster 80
alfam2 ALF MC1 / Apple Music II
ap16 IBS AP-16 80 column card
ap16alt IBS AP-16 80 column card (alt. version)
applicard PCPI Applicard
arcbd Third Millenium Engineering Arcade Board
cffa2 CFFA2000 Compact Flash (65C02 firmware, www.dreher.net)
cffa202 CFFA2000 Compact Flash (6502 firmware, www.dreher.net)
corvus Corvus Flat Cable interface
diskii Apple Disk II controller
diskiing Apple Disk II NG controller (16-sector)
diskiing13 Apple Disk II NG controller (13-sector)
dx1 Decillonix DX-1
echoii Street Electronics Echo II
echoiiplus Street Electronics Echo Plus
ezcgi E-Z Color Graphics Interface
ezcgi9938 E-Z Color Graphics Interface (TMS9938)
ezcgi9958 E-Z Color Graphics Interface (TMS9958)
mcms1 Mountain Computer Music System (card 1)
mcms2 Mountain Computer Music System (card 2)
memexp Apple II Memory Expansion Card
midi 6850 MIDI card
mockingboard Sweet Micro Systems Mockingboard
mouse Apple II Mouse Card
parallel Apple Parallel Interface Card
pcxport Applied Engineering PC Transporter
phasor Applied Engineering Phasor
ramfactor Applied Engineering RamFactor
sam Don't Ask Software S.A.M.
scsi Apple II SCSI Card
softcard Microsoft SoftCard
ssbapple Multitech Industrial SSB Apple speech card
ssc Apple Super Serial Card
ssprite Synetix SuperSprite
swyft IAI SwyftCard
thclock ThunderWare ThunderClock Plus
themill Stellation Two The Mill
tm2ho Applied Engineering TimeMaster H.O.
twarp Applied Engineering TransWarp
ultraterm Videx UltraTerm (original)
ultratermenh Videx UltraTerm (enhanced //e)
videoterm Videx VideoTerm
vtc1 unknown VideoTerm clone #1
vtc2 unknown VideoTerm clone #2
zipdrive Zip Technologies ZipDrive