This thread seems to have turned into a discussion on the actual meaning of strictly better, and segura brought up the example of Mining Village, which would be strictly better than Village at the same cost. This got me thinking about what can actually make a card strictly better (in a purely pedantic context) than another card. Here is the list I came up with:
"Strictly better effects" (not counting Possession):
- Adding a choice (such as Mining Village)
- Adding
a vanilla bonus other than +Cards* (+Cards are not strictly better in draw to x engines, or if you don't want to trigger a reshuffle) +Buy
- Adding
+Coffers, +Villagers, +

or +

-
Replacing +
with +Coffers or Replacing +Actions with +Villagers
- Adding VP value to a card which is already a Victory card
- Any ability adding any other "strictly better ability" to another card (such as non +Cards Adventures tokens)
Effects which would be "strictly better effects" if you removed one or two specific cards from the game:
- Adding +

(Storyteller), +Actions (Storyteller or Diadem)
- Adding +Coffers (Swashbuckler) or Replacing +

with +Coffers (Black Market and Swashbuckler)
Can anyone come up with something not on the list so far?