Archive Trap If you're a Modern player, Archive Trap is one of the top mill cards to pick up
You also can't really grind out a game of commander in the same way that you might 1v1, going for card value, trading up a little, keeping track of cards in hand, and trying to essentially create more threats than your opponent can answer
Cemetery Puca: Very interesting
Penny's Illustration Rare card hardly screams adventure, but then, it's this more somber stature that makes the whole thing tick to the tune of about $30 and counting
Macro Cosmos This trap card is so powerful that its been limited to 1 copy per deck and I dont see that changing any time soon
It's also worth mentioning that, while I have taken into account the secondary market value of some Ninja Spinner cards for this list, some of these are my top choices simply because they look neat