COMMONS: wall and militia for obvious reasons (any free quick common cards are a must)
Graceful charity, because its a great card in the first place, and with the new bug that makes it work with wall and militia, its also a must!
Unicorn: i think its a nice card with decks that require lots if gems and not much recruits. it also counters light infantery....
Merchant: I put it in nearly every decks, nice to have choice of the ress u want
Don't be hasty: ppl all use quick cards so.... you often can -3 or -4 stock them with this card for free. in addition to this, you can decide not to use it when he gets shitty cards, and use it when he gets great cards
UNCOMMONS:
Pegasus for obvious reasons
Locust swarm is nice with swift heavy decks (like mage decks)
RARE: the obvious order of white lotus, prince thieves
also master of the past
and Tyran's pride
all great