In practice, there arent too many dedicated payoffs though
Archmages Charm is extremely pushed, a solid permission spell, a good way to build card advantage for hitting land drops, and a fantastic tool against Deaths Shadow, Wild Nacatl, Goblin Guide, Pyxis of Pandemonium, Champion of the Parish, Aether Vial, Delver of Secrets, Hardened Scales, Amulet of Vigor, Benthic Biomancer, Glistener Elf, Noble Hierarch, Viscera Seer, and sometimes even Hexdrinker (just to mention a few)
The most prized cards of the bunch are the Imagine Courageous Critters from Bloomburrow s non-Standard offerings
Secret Lair x Monster Hunter: The Hunters Grand Abolisher, featuring Tigrex Armor with Bone Scythes from Monster Hunter Generations and Monster Hunter Freedom 2
The most extreme example of this is the One of One Ring
The most critical is the size of your collection