Honorable Mention: Golem
It’s crazy effective in an Action-heavy deck. It keeps your engine flowing even while it’s greening. It acts as a source of fake +Actions. It cycles your deck to keep playing devastating attacks. It is great for a no-Treasure engine. It leads to complex, crazy combos with Counting House or Tactician/Library.
But none of that matters when you play Golem with a hand of two Provinces, and it draws Trading Post …
Probably the most underappreciated card in Dominion. Apothecary/Warehouse, Apothecary/Native Village, and probably countless more combos are surprisingly dominant, and the common theme throughout is that it’s really hard to slow down a deck that is built around what can potentially be a +1 Action / +5 Cards card.
The major criticism is that it doesn’t really blend well into many standard engines. Its +1 Action / +1 Card means it’s never truly bad, but it doesn’t shine nearly as brightly as when you build your deck around taking advantage of its unique abilities.
Setting aside how annoying Alchemist chains are on Isotropic (both to clean up and to watch), the ability to keep Labs on your deck is just unbelievably awesome. It means you never have draw problems, and that you can (almost) always combo your Alchemists with King’s Courts and Throne Rooms. It’s kind of vulnerable to handsize attacks, but I’d rather have a good hand that I might be forced to discard some of than a bad hand any day.
Of course, you have to keep drawing the Potion … hmm … if only there was a way to keep increasing your handsize so you could draw the Potion … hmm … oh right! With Herbalist or Cellar, Alchemist gets absolutely obscene, since once you get two or three of them they can stay on your deck almost forever.
Despite its awkward cost, Vineyard is one of the very best alternative VP strategies. 1 VP for 3 Actions, as it turns out, is a very good deal when you’re building a deck full of King’s Courts and such, which coincidentally happens to be the kind of deck that benefits from alternative VP strategies anyway. It has excellent synergy with most of the other Alchemy cards that depend on Actions, but is sometimes worthwhile even when it’s the only Potion card on the board. It does heavily, heavily depend on a source of +Buy, because otherwise it is a total pain trying to buy them.
In a way, Vineyard is the defining card of Alchemy. It’s an excellent example of how Alchemy has more than just a Potion theme; it’s themed around playing as many Actions as possible.
2. Scrying Pool
Scrying Pool is almost a cheat, since it lets you build giant Action chains without any of the +Cards ordinarily needed to draw them all. It’s rather dependent on trashing, but if you can get your deck thinned and consisting mostly of Actions, it makes Action decks significantly easier to get going. It’s usually dependent on some source of +Actions so you can play all of your Actions, but with the possible exception of King’s Court, no other card generates turn logs as ridiculous as Scrying Pool.
It’s truly upsetting, having Familiar at #1, but there was no way around it. Familiar is probably the best attack in the game so far, and one of the only attacks that can be chained without sputtering out. Plus, it’s not total crap after the Curses are gone, it’s great Apprentice/Salvager fuel … ugh!
About the only thing it’s kind of vulnerable to is Horse Traders, since you’ll be dependent on it to move through your deck after the Curses are gone, and each play lets your opponent potentially increase his handsize by one. But this is nitpicking. Aside from its cost, there’s no reason not to get a Familiar.