There was one card I was going to suggest since I am in love with it as much as Aston and
Oketra's Monument, but Vince already beat me to it:
This card has been a fixture of standard, pauper and cube since it was printed for me, even though it took a little bit for me to recognise it's potential.
Can chip in early, is a decent chump blocker, is decent to flicker, is a human, includes artifact synergy and draws you a card.
There is no opportunity cost to this card. It is just purely great value. Would never cut.
So instead let's go with 3 cards that haven't been mentioned:
This is a great card that helps filter in the early game while leaving a roadblock in the way to becoming a 4/4
Thoughtflare when you flood out.
Having cards that do multiple things means there are less non-games, which is what we all want right?
The Bi-Cycle lands have been decent. The biggest issue is that they don't have the full cycle yet (just allied colours). I think I like these slightly less than the scry lands but making them fetchable and people liking land-based cards more (see
The Gitrog Monster) have seen these slot into the cubes I run.
This card is hilarious. I have really enjoyed the mini-game it makes (I don't want to get hit for another one to appear) and was worth swapping bonesplitter over to this.