Well, Red, Blue, and Yellow were some of my first games (I don't know how I got them, my parents weren't big into buying me videogames)... and that started my love for videogames...
Then Gold and Silver came around... I got Silver the day it came out, went to school the next day, and every other guy was jealous (some girls were too) because I had it and they didn't... Got Gold for Christmas, and then then I entered a hiatus... Never got Crystal, don't know why...
Ruby and Sapphire showed up and I didn't really have any interest by then... until they started talking about FireRed and LeafGreen and Emerald... Somehow that brought me back into the games... Got two Emeralds and FR and LG... they never had ruby or sapphire around when i went in, so i decided to get two emeralds... now they have Sapphire again, it's like they are mocking me...
And now we're to the present Generation... I got Diamond, I don't know, a few months after it came out, got Pearl shortly after that, and got Platinum a week after it came out... Now I'm waiting for SoulSilver and HeartGold to come out...
So, I guess I like Pokemon because it is one of the few things from my childhood I enjoyed that I still can... if only I could stay up 'til four in the morning and wake up and six and feel completely rested... It's also consistent for the most part... And I just really enjoy it... (Wow, that was a really long explanation)...