@shoofle jk. I have a soft spot for cassettes, but I only have a few. Floppy disks confer immense satisfaction. CDs are pretty. CD roms w/ printed labels that have a subtle texture from dithering are a favorite. I love cartridge based game media, though lately my gameboy games have been breaking my heart as their batteries die.
However, I think at the top of the list is old CD RWs with hand written labels.