I thought I'd share some of my own 'smallest plants'.
I included a US quarter in the photos for scale.
Mammillaria elongata var elongata
Easter Cactus - orange (I think)
Donkey Ears Kalanchoe pups
Haworthia cymbiformis
My original plant died in the center, but it exploded also with little pups. I'm happy with the results.
assorted Haworthia
NOID Aloe pup
Crassula ovata obliqua
The jade plant with a point at the tips of the leaves.
Variegated Black Gem Aloe
This thing has been this size for what feels like forever.
Austrocylindropuntia subulata 'Snow Pine'
Opuntia elata
Split Rock Succulents
Echinopsis 'Rose Quartz'
Thimble Cactus