Thoughts on my favourite entries:
Field
Types: Action
Cost: $4
Reveal the top 4 cards of your deck. Put one of each differently named card revealed into your hand. Discard the rest.
Nice terminal draw variant. This is probably nice in engines, as you can find the most important cards more easily compared to Smithy, but this is overall a bit weaker than it. Not every card needs to shine in all possible kingdoms though.
Scarecrow
Types: Action
Cost: $3
+2 Cards. +2 Actions. Reveal your hand. Discard duplicate cards one at a time until you have no duplicate cards in hand.
As it's already been mentioned, this card is especially nice with Menagerie. What I also find interesting in this is that even if it's a reversed Menagerie, it's still as its best in same kind of situations, where you have trashed your starting cards or have strong shifting.
Vanguard
Types: Action
Cost: $5
+2 Cards. +2 Actions. +1 Buy.
While this is in play, when you buy a card, trash each copy of that card you have in play.
While this might be too good for a 5-2 opening and have balance issues, it's at least very interesting. It makes you do some tough decisions - do you want to play that Market, if you are aiming to buy one this turn?
Pariah
Types: Action
Cost: $5
Gain a card costing up to $6. Each other player may gain a Curse. If he does, he gains a copy of the card you gained.
This is a very interesting gainer. Its best use would probably be to gain some cards your opponent doesn't want, especially 5's - for example if you're going for an engine and your opponent is going for a terminal draw Big Money, he might not want to gain a Bazaar for the cost of a Curse.
Showman
Types: Action
Cost: $3
+1 Action. Reveal a card from your hand, then reveal the top card of your deck. If they don't match, +1 Card and +$1.
This is also one of my favourites. It's simple but strategic - and it really encourages variety in your deck.
Dairy
Types: Action
Cost: $5
+3 Cards. Reveal then discard any number of cards. If you discarded any cards, gain a card with cost up to $1 plus the number of differently named cards discarded. If you discarded at least 3 differently named cards, +1 Action.
This card has many uses. It can be used for terminal draw, gaining or shifting - and it has that ability in a cool way.
