Well, I guess that can be debated, but it certainly was the game that put pro football on the map. The whole country got to see the game on TV except those in the NY metro area as all home games were blacked out then. We had a rotating antenna so we watched the game on the CBS affiliate out of Philly.
https://www.foxnews.com/lifestyle/this-day-history-dec-28-1958-colts-beat-giants-nfl-title-greatest-game
East coast bias. And recency bias.
I remember hearing about it from my grandfather as a child.