I do like the Mario games and I got New Super Mario Bros before I got Pokemon Platinum. However, they were a bit challenging to me when I was 5 or 6 years old. They are both great series but I have to go with Pokemon.
Zelda<(^_^)>Been in love with it since I got my used N64 and got Ocarina of Time, I did also nearly play Wind Waker, but that was stolen from me Dx Anyways definitely has to be Zelda for me, Pokemon is a close second. Probably gonna splurge on my upcoming birthday on the new Pokemon as well as possibly Wind Waker, though; I would have to buy a Wii U for that gosh darn it xD
I'm surprised that people barley played Kirby in this thread.
Not to say that Kirby is better than these franchises (Although Super Star can go up with Mario World, Majora's Mask, Pokemon Black 2 & White 2 as being tied with my favorite games of all time), but I'm pretty sure that people played like 1 or 2 games here.
Pokemon for me. I've only played one Zelda game which I never finished, back when I was about 8. And I've played and liked Mario and Kirby games but Pokemon was a HUGE part of my childhood and I still play every new game that comes out; I don't think I'll ever really outgrow it.