This article is for beginning players; I don't expect experienced players to get very much out of it, although I hope it will be fun for them to debate.
Experienced and inexperienced Dominion players alike love arguing about which cards are better than which others. And indeed, if you wander this site, you can find years worth of rankings, and of arguments about what the true definition of rankings should be, etc.
This list is intended to contribute to that discussion, but it is not a ranking. Rather, it's a "report card," which assigns each card a grade.
When you look at a board, one quick skill is to identify key cards and to build a strategy around them. This list grades cards by how likely they are to be "key cards." There are only three grades, and most cards get a B.
A = almost always a key card. May need one or two helpers to be truly dominant, but those helpers arise frequently enough that we always worry about this card a little before the game starts: do we want it, and if we don't, how do we defend against our opponent who will likely buy it? A classic example of a solid A card is Goons.
B = not usually a key card, but likely to be useful. We may well buy one or more of these to support a strategy. Sometimes, this card can be a key card, with the right combination of helpers; however, the first strategies we look for don't revolve around B cards. A classic example of a B card is Laboratory. Almost every deck is improved by Laboratory, but it's not the center piece of any strategy. A different sort of example is Gardens. If we look at a board and there are not a lot of great strategies available, we may consider a Gardens-centered strategy, but we need to find helpers.
C = rarely worth reflecting about. We don't expect to lose too many more games if we simply pretend this pile isn't there. Sometimes a card in this pile can be useful if it is, for instance, the only card on the board that provides +Buy. For example, Woodcutter is a C card. Of course every pile has a purpose, and the best players can and do use C cards to their advantage.
We will use + and - in a category to mean a card is borderline between two categories. A grade of A+ is not given; for the purpose of this list, it doesn't matter which A cards are better than the others. Note that having a higher grade does not necessarily mean being a "better card." For example, Laboratory is almost certainly a better card than Bridge, but is less likely to be a key card and so has a lower grade.
The grades are based on 2-player Dominion; many cards would change grades in multiplayer. This list is obviously my opinion. In particular, the Adventures cards are not graded because I have only played a few games with them.
Warning: Card interaction is 98% of Dominion strategy, and this report card cannot help you with it at all. For example, Chancellor and Stash are both solid C cards, but the combo Chancellor/Stash would be at least an A-. More fundamentally, knowing which cards in a kingdom are good doesn't tell you how to buy them, how to build a deck around them, and how to play them. But it's a start.
Base
2
Cellar B
Chapel A
Moat B-
3
Chancellor C
Village B
Woodcutter C
Workshop B-
4
Bureaucrat C
Feast C
Gardens B
Militia B+
Moneylender B
Remodel B
Smithy B
Spy C
Thief C-
Throne Room B
5
Council Room B
Festival B
Laboratory B
Library B
Market B
Mine B-
Witch A
6
Adventurer C-
Intrigue
2
Courtyard B
Pawn B
Secret Chamber C
3
Great Hall C
Masquerade A
Shanty Town B
Steward A-
Swindler A-
Wishing Well B
4
Baron B
Bridge A-
Conspirator A-
Coppersmith C
Ironworks B
Mining Village B
Scout C-
5
Duke A-
Minion A
Saboteur C
Torturer A-
Trading Post B
Tribute B-
Upgrade A-
6
Harem B
Nobles B
Seaside
2
Embargo C
Haven B
Lighthouse B
Native Village B
Pearl Diver C
3
Ambassador A
Fishing Village A
Lookout B
Smugglers B
Warehouse B
4
Caravan B
Cutpurse B
Island B
Navigator C+
Pirate Ship C+
Salvager B
Sea Hag A
Treasure Map B
5
Bazaar B
Explorer C
Ghost Ship A
Merchant Ship B
Outpost B+
Tactician A-
Treasury B
Wharf A
Alchemy
2
Herbalist C
5
Apprentice B+
P
Transmute C-
Vineyard A
2P
Apothecary B+
Scrying Pool A
University B+
3P
Alchemist B
Familiar A
Philosopher’s Stone C
4P
Golem B
6P
Possession A-
Prosperity
3
Loan B
Trade Route B-
Watchtower B
4
Bishop B
Monument B+
Quarry B+
Talisman B
Worker’s Village B
5
City B
Contraband C+
Counting House C-
Mint B
Mountebank A
Rabble B
Royal Seal C
Vault B
Venture B
6
Goons A
Grand Market A
Hoard B
7
Bank B
Expand B
Forge B+
King’s Court A
8
Peddler A-
Cornucopia
2
Hamlet A-
3
Fortune Teller C
Menagerie A-
4
Farming Village B
Horse Traders B
Remake A-
Tournament A
Young Witch A
5
Harvest C
Horn of Plenty B+
Hunting Party A
Jester B
6
Fairgrounds B+
Hinterlands
2
Crossroads B
Duchess C
Fool’s Gold A-
3
Develop B-
Oasis B
Oracle B
Scheme B
Tunnel B+
4
Jack of All Trades A-
Noble Brigand B-
Nomad Camp C
Silk Road B
Spice Merchant B
Trader B
5
Cache C
Cartographer B+
Embassy B+
Haggler A-
Highway A-
Ill-Gotten Gains A
Inn B
Mandarin C+
Margrave A-
Stables B
6
Border Village B+
Farmland B
Dark Ages
1
Poor House B-
2
Beggar C
Squire B
Vagrant B-
3
Forager A
Hermit A-
Market Square B
Sage B
Storeroom B
Urchin A
4
Armory B
Death Cart C
Feodum C+
Fortress B
Ironmonger B+
Marauder A-
Procession B
Rats B-
Scavenger B
Wandering Minstrel B+
5
Band of Misfits B-
Bandit Camp B+
Catacombs B
Count A-
Counterfeit A-
Cultist A
Graverobber B
Junk Dealer A-
Knights B
Mystic B
Pillage C
Rebuild A
Rogue B
6
Altar B
Hunting Grounds B
Guilds
2
Candlestick Maker B
Stonemason A-
3
Doctor B
Masterpiece B
4
Advisor B
Herald B
Plaza B
Taxman B-
5
Baker B
Butcher A-
Journeyman B
Merchant Guild B+
Soothsayer A-
Promos
Black Market A-
Envoy B
Walled Village B
Governor A
Stash C
