The Immortal Game (Anderssen, 1851)

London, 1851 — a casual game between rounds of the first international tournament. Adolf Anderssen (White) versus Lionel Kieseritzky. White sacrifices a bishop, BOTH rooks, and finally the queen… and delivers mate with three minor pieces.

A warning before you enjoy it: this is romantic-era chess — some of Black's greed and White's generosity wouldn't survive an engine. That's not the point. The point is the purest lesson ever taught about ACTIVITY versus MATERIAL. Count Black's developed pieces at the end.