Final Fantasy VI - It literally brought me back to gaming. I'd gotten bored with the SNES, for the most part, and had drifted away from video-games. A friend of mine wanted to go to a used game store, though, so I went with him. Looking around, I found a copy of FF VI, which brought back memories of the first Final Fantasy on the NES, which I enjoyed a lot. I was pulled in from the very start and will never forget watching those mecha walk through the snow in the opening video.
ICO - The atmosphere was like nothing I'd ever experienced in a game before. It was like a poem that you could play.
Suikoden II - I consider this game to be a masterpiece. It was just so good in so many areas, from story, to characters, to gameplay.