Most played cards in Reanimator:

2 Decks
Persist
8 copies - 4 average
Prismatic Ending
8 copies - 4 average
Archon of Cruelty
8 copies - 4 average
Thoughtseize
5 copies - 2.5 average
Flooded Strand
4 copies - 2 average
Unmarked Grave
4 copies - 2 average
Spreading Seas
4 copies - 2 average
Polluted Delta
4 copies - 2 average
Grief
4 copies - 2 average
Grisly Salvage
4 copies - 2 average
Teferi, Time Raveler
4 copies - 2 average
Verdant Catacombs
4 copies - 2 average
Ephemerate
4 copies - 2 average
Marsh Flats
4 copies - 2 average
Mulldrifter
4 copies - 2 average
Chalice of the Void
4 copies - 2 average
Counterspell
4 copies - 2 average
Faithful Mending
4 copies - 2 average
Knight of Autumn
3 copies - 1.5 average
Kaya's Guile
3 copies - 1.5 average