I've got waaaaay too much stuff that's much older than most of the items already posted here (and probably older than a lot of members), but it's 4:15 AM here right now so I don't really feel like digging everything out atm
You'll have to make due with few HDDs for now..
Seagate ST351A/X (40MB singleplatter. one of the last stepper drives)
http://www.techpowerup.com/forums/attachment.php?attachmentid=46140&stc=1&d=1331434794
http://www.techpowerup.com/forums/attachment.php?attachmentid=46141&stc=1&d=1331434813
Seagate Marathon 260SL (2.5" 10mm, 262MB, 4000rpm, 120KB Cache, from 1994)
http://www.techpowerup.com/forums/attachment.php?attachmentid=46142&stc=1&d=1331434829
Toshiba MK2124FC (2.5" full height (20mm), 130MB, 2 platters, 3200rpm, 32KB Cache, from 1991)
pretty bad pic but anyways
http://www.techpowerup.com/forums/attachment.php?attachmentid=46143&stc=1&d=1331434838
One of the drives has a sticker that says "do not low level format." Why would that be?
I also have one Quantum Bigfoot of each series (CY, TX, TS), a Seagate Barracuda 4GB 3.5" full height SCSI drive from ~1996 (?) and a HP SureStore Disk 2000LP 2GB SCSI HDD from January 1996 somewhere.
And a 40MB NEC MFM HDD and a WD/Tandon 20MB MFM HDD plus the accompanying Amstrad PC1640 (8086 8MHz, 640KB RAM) they came out of / are in atm.
Oh and yeah.. all of this is still fully functional
edit: edited the IMG tags to URL cause the forum doesn't seem to auto-resize them (probably because the pics are in portrait, not landscape)