1. Xenosaga: Episode I
2. Tsukihime
3. Final Fantasy VIII
4. Beyond Good and Evil
5. Tokimeki Memorial ~ forever with you ~
XD I'm so predictable. So ~ some explanations:
Xenosaga - I fell in love with this game within the first half hour of gameplay. The characters, the overall story, the battle system... I love it. And no matter how many times I replay it, I swear there are about three scenes that always make me cry. The only reason Episodes II and III aren't listed is because II was a bit of a letdown after the first one, and I haven't played III yet.
Tsukihime - Computer games count! >.> Anyway. This gets the number two spot if only because of the Hisui and Kohaku routes. The storyline(s) of the game are just... so detailed, and you can really get drawn in.
FFVIII - One of the later FF games I played, and it's still sitting in one of my top spots. I like the characters, I love the whole magic-draw system, and I don't even mind randomly wandering around the worldmap for hours because I always find neat stuff.
Beyond Good and Evil - One of the most underrated games ever, I swear. The characters are awesome. The gameplay is awesome. And it's likely the only platformer I can actually manage to do well in. It's unique and interesting and would likely have gotten higher on the list if it were a bit longer.
Tokimemo - I'm a dork and admittedly, I enjoy playing dating sims. This one makes me laugh no matter how many times I play it, from the random koala attacks to the festival where a giant mecha accidentally trashes the campus. It's in my top five for its lightheartedness and fun.