all standard legal cards mtg 6 Crazy Valuable Standard-Legal You Probably Own mtg standard card database OC]

My favorite is Fumiko the Lowblood, who has been reprinted before and has an odd pair of abilities

If your basic lands tap for mana, you make triple that amount

Another legendary land, Tolarian Academy can tap to add one blue mana for each artifact you control

Aang, Airbending Master Allied Teamwork Appa, Steadfast Guardian Captain's Claws Gather the White Lotus Gideon, Ally of Zendikar Hook Swords Invasion Reinforcements Iroh, Tea Master Jasmine Dragon Tea Shop Katara, Water Tribe's Hope Kyoshi Battle Fan Kyoshi Warriors Loyal Fire Sage Match the Odds Path to Redemption Pretending Poxbearers Retreat to Emeria Sokka and Suki Sokka, Tenacious Tactician Suki, Courageous Rescuer Suki, Kyoshi Warrior Sun Warriors Tolls of War Treetop Freedom Fighters Unified Front