Leaf Green, Diamond, Emerald, Pokemon Battle Revolution all kept me up until the hours of the early morning.
Leaf Green: Playing a 1st gen remake in better graphics, animations, sprites, etc is exciting! It was a dream come true to be able to play the "good ol' days" again but in a better way. Mewtwo was a huge reason also. I wanted Mewtwo badly, and it was a fun time trying to catch it.
Diamond: When it was released, I jumped up for joy and bought it right away. I stayed up many nights just playing it as much as I could seeing everything I could see and exploring every spot in the game.
Emerald: The Regis were a blast to catch, Rayquaza was even better, he made me drool at night before I caught him. Kyogre and Groudon were also "drool-material." The Battle Tower was also addicting, challenging, but addicting....
Pokemon Battle Revolution: What an amazing game for hardcore pokemon fans. The graphics made me orgasm for hours, lol. I spent so much time dowloading pokemon from my Diamond version and beating all the colosseums and matches in Stargazer Colosseum, I also spent many hours trying out every move to see what the animation looked like in the game with its shimmering graphics. I also wanted the mystery gift Magmortar, Electivire, and surfing Pikachu.