It's really really strong card which you can almost never ignore vs. coo-coo bananas strong card which you usually can't ignore.
Which is which?
OK. We've already had the goons/KC debate. I suggest if you want to discuss it, read though all the posts here first (http://forum.dominionstrategy.com/index.php?topic=1668.0) and then keep it in that thread. Let's keep this thread to talk about other things?
The whole point of these discussion threads is to argue over which card is better. There really isn't much argument about most of this list, which is pretty obvious give or take a spot or two in the middle. So why not talk about Goons vs. KC?
KC is the better card. Getting KC paired with the right card can often mean game over. Also, getting that engine to go off means game over. Playing Goons doesn't mean game over, especially because your opponent will be doing the same to you. On certain boards, ignoring KC will mean your death!
On a very very high percentage of boards, ignoring Goons means your death too. KC and Goons are the two best cards for engines, bar none, and you can make a case for either one being #1 or #2. KC makes engines a zillion times better, and can make engines out of stuff like Pearl Diver. But even with KC, sometimes it's just not worth it to go engine- say, a BM-Masquerade match with no +Buy. Goons is automatically always the best linchpin for an engine, because it stacks so powerfully and attacks too, such that if any engine is even remotely feasible it is suicide not to go Goons. But, of course, sometimes an engine is physically impossible: say, there are no Villages, or it's a Mountebank-notrash game.
So I think they're roughly even in engine setups: both basically always mandatory, and almost always the most important card or very close to it. The difference is in boards which lean heavily Big Money and can't support engines at all: King's Court is often a waste here, whereas Goons
is still one of the very best choices you can make for your terminal slots, eclipsed pretty much only by cursing and maybe Wharf (and maybe you still want Goons when the Curses run low). The fact that Goons is still a great card even in unfavorable boards is what gives it the edge in my eyes.
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But yeah, whether you prefer KC or Goons they're obviously #1 and #2 by a wide margin, I think we can all be glad that Grand Market is at #3 where it belongs.