Bayou

A land that taps for either color and pays nothing to do it: no life, no tempo tax, no reveal condition, no requirement that you already control a basic. Being a Swamp and a Forest is the load-bearing detail. It is fetchable by any effect that searches for a Swamp or a Forest, it answers to every card whose text keys on those subtypes (a roster that has only grown since 1993, from Lifeforce-era hosers through modern fetchlands), and it offsets that typing with nothing at all. Every subsequent two-color land cycle has been designed in reference to this one: the shocklands taxed it two life, the check lands taxed it a stumble under the wrong opener, the surveil lands simply entered tapped. Each cycle is essentially a different way to price the same effect without printing it outright. Because the original ten can never be reprinted, the rate they set has become a permanent ceiling rather than a starting point: this is the standard golgari fixing gets measured against, and nothing legal in the formats where it is legal has ever quite matched it.