6 Dryad Arbor An Awe-Inspiring Design Anomaly Dryad Arbor may stretch the colloquial definition of Creature Land slightly, but its such a pure iteration of the concept that it deserves a place on this list regardless
Neglecting the mana curve and mana base
Illustrated by Filipe Pagliuso Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp
Due to the effect of Cybernetic Horizon, you can cover 4 materials by dumping 3 cards + searching 1 card, and depending on the type of card you discard, you can additionally dump 1 card and search 1 card, making it possible to secure as many as 6 materials with a single card
In terms of content, it's a fairly standard gate, with 3 Scenarios, one practice match to teach you how the archetype works, and 3 proper duels, both with a loaner deck and with your own
After all, it is the sellers property to do with it what they wish