Although it isn't the first survival horror game, many would consider Resident Evil to be the game that put horror games in the public conscious. Starting in 1996, the franchise sold millions of games in multiple console generations and earned Capcom billions of dollars.
However, one game in the series didn't sell so well, making it a valuable collector's item.
Resident Evil: Gaiden came out in the U.S. in 2002 for the Game Boy Color. When it released, reviewers didn't quite know what to make of it and gave it below average scores (we're talking 4/10s, here). This, of course, resulted in the game not selling all that well.
But a game selling poorly is music to a collector's ears as copies of Resident Evil: Gaiden can now go for $200-$300 for a sealed copy. That's a far cry from the original price of $29.99.