Super Metroid, the first really amazing game I ever played. Never before had I been so immersed by the atmosphere and actually enjoy listening to the music as well, that's a winning combination right there.
Lineage 2, it has many flaws and not as fast paced MMO like WoW but it was amazing at release and the design was superb. The new chronicles are awful, some things they did improve on but they also killed what made the game great when they tried to transform it into WoW. Also, the botters and farmers didn't help either. I wish I could show you chronicle 1 so you could see why I would defend it.