[lordkingod]

From Wikipedia:

"Atari optimistically had produced 5 million cartridges, half as many
as there were Atari game consoles in existence at the time. There is
an urban legend that Atari secretly buried the millions of unsold
cartridges in a landfill near Alamogordo, New Mexico in 1983 [2],
though both Howard Scott Warshaw and Ray Kassar dispute this."

Turns out the rumour was true:

http://www.snopes.com/business/market/atari.asp