In PlayStation 2 (and other consoles, for what I could find), when you play Need For Speed: Most Wanted, if it finds that the memory card contains save data for Need For Speed: Underground 2, you receive an extra $10,000 at start in Career mode.
Is there any PlayStation 1 title that could read game data for another game and use it somehow? (I presume it would be to the player's advantage if so, but I'm interested in any kind of effect).