Moving beyond that into multi-color, Orzhov does some pretty interesting stuff with enchantments
High-end, Reserved List cards (a list of cards the publisher has promised never to reprint) have proven to be exceptional long-term investments
Mime will effectively take only 1030, which will keep it alive for quite a long time
032 Espurr

Adaptive Sporesinger Additive Evolution Alacrian Jaguar Ancient Adamantoise Animus of Predation Apothecary Stomper Appeal // Authority Awakened Skyclave Beacon Behemoth Bear with Set's Mechanic (playtest) Big Bertha Bighorner Rancher Bitterbow Sharpshooters Brambleguard Veteran Briarbridge Tracker Brushstrider Built Bear (playtest) Cemetery Prowler Chancellor of the Tangle Circle of Elders Cryptid Inspector Curious Altisaur Deepwood Denizen Diplomatic Relations Dire-Strain Brawler Dragon Sniper Earthbending Student Earthrumbler Elder Gargaroth Elfhame Wurm Embodiment of Insight Emeritus of Abundance End-Raze Forerunners Enduring Vitality Esika, God of the Tree Excavating Anurid Fangorn, Tree Shepherd Feasting Troll King First Responder Flycatcher Giraffid Galewind Moose Gamma Grotesque Gargos, Vicious Watcher Garruk's Warsteed Gatebreaker Ram Giant Beaver Glacier Godmaw Gnarled Grovestrider Gnarled Sage God-Eternal Rhonas Goldvein Hydra Gorm the Great Grabby Tabby Greenwood Sentinel Guardian of the Great Conduit Haldir, Lrien Lieutenant Harmonious Emergence Harold and Bob, First Numens Hercules, Prince of Power Heronblade Elite Hierophant Bio-Titan Hit-Monkey Honor Troll Honored Hierarch Howl of the Hunt Howling Galefang Hulkling, Burgeoning Bruiser Interplanar Brushwagg (playtest) Invoke the Ancients Jewel Thief Joraga Bard Kamahl's Will

Eevee and every single Eeveelution got a beautiful SIR card, and most of these SIRs are worth a few hundred dollars