Metal Gear Solid.
If you were playing videogames in the 90s you know what I mean...
You can enjoy the levels design, the stealth action or even joke with the runts and their predictable patterns, but you are always going forward expecting a huge boss fight against an incredible enemy.
Any boss fight (not only the final fight) within the game has its own plot developed during the fight. That forces you to stay sharp and alert at every word he/she says and to discover the only moment while he/she will be vulnerable to your attack... Or maybe wait until the game breaks the 4th wall and lets you take some advantage of it...
An old masterpiece, revolutionary at its time and my number 1 videogame for the glorious PSOne. What else could I say not mentiened before about this one?