Shatterskull Smashing / Shatterskull, the Hammer Pass Shatterskull Smashing isnt an incredible rate on a fireball, but its worth the opportunity cost of running a card that, at its absolute worst, is just a tapped Mountain
Unlike the previous two cards, Swords to Plowshares costs well below $1, but its without a doubt the most popular card included in Fourth Edition
It is a three for one not a two for one and can cost half the price
That said, Eldrazi Displacer has been an incredibly impressive card in all formats, and its a card I like having in my deck against G/W Tokens specifically
Righteous Valkyrie ( Kaldheim) Angels suffer from being expensive to cast, and Righteous Valkyrie is one of the better Angels below four mana
Keep in mind that this isnt a list of the best discard effects in MTG