I can't. I just can't pick something else. Zelda has been a huge part of my life since I was little. Granted, so has Pokemon.. but LoZ was more of a family thing.
My cousin introduced me to Pokemon and Digimon, sure. But my father and my sisters introduced me to Zelda. There's all these fond memories of playing a save file that was in my sister's name. It got to a point where I almost named every save file after aforementioned sister.. it felt wrong not having her name, haha.
Zelda, of course! Mario games are almost always fun, but isn't really my go to franchise for Nintendo, and I really want to play more Kirby games, the couple I've played are pretty fun! Pokemon's pretty fun too but interests me about as much as Mario and I've played far more Mario than Pokemon..
Pokemon, because it is the first game I got extremely addicted to and it was the game that sparked my interest in games. It is also what got me to go on these forums in the first place. I must say it is one of the games that made a huge impact on me.
I've always loved Kirby. My favorite Kirby game was Amazing Mirror. I'm holding out hope that there will be another Kirby game like that someday. (while also secretly hoping for a Kirby RPG or another air ride) ^^;