Off the top of my mind, stuff that I've used and still have lying around:
- 5.25" floppies (DSDD, Commodore 64; I think I may have a few HD floppies for PC but I'm not sure if I have a drive for them)
- 3.5" floppies (HD and some DD, mostly for PC; I have a few PC carcasses that have floppy drives, but I do also have a working USB floppy drive)
- Cassette tapes (Spectravideo, Commodore VIC-20, Commodore 64)
- ROM cartridges (same as above, plus game consoles)
- Iomega Zip (not sure if the Zip floppies I have have anything relevant; the USB Zip drive is in box somewhere)
- Iomega Jaz (two disks; not sure if the drive I was actually working last time I used it, could be completely hosed by now, Iomega didn't exactly have a good reputation)
- A few IDE/PATA hard drives (not sure of the condition)
- Bunch of CD/DVD/rewritables, I think I have a few unused CD-Rs/DVD-Rs too, never had a Blu-Ray drive for computers
- USB sticks and hard drives of various descriptions
- microSD cards used with Raspberry Pi
Funny thing is, I think I have no extra SATA hard drives and modern SSDs lying around, because most of the computers I have that use them are still in operation.