Back in the day, when there were only the first 150 (which I thought was a LOT back then), mine was Butterfree!
When generation 2 came by, I always wanted to use a Kingdra! I thought it was one of the greatest pokemon I had ever seen. It's kind of funny that I'm mentioning this here of all places, because I always taught my Kingdra in Silver to use Attract. (And it was a girl, so maybe that's why I love her so much!)
Then when generation 3 came by, there were a lot of new pokemon, and I was all, "Okay, I can do this," and then I saw Kingdra again, and it looked even greater there than it did before!
Over time, however, my interests took a turn for the better, or worse (I don't know the difference anymore), and soon enough, the 4th generation came by, and I saw al the new pokemon there. At first I was like, "What? These are all just new evolutions to old pokemon," but then I actually got used to them, and now I'm all, "It's all about Ambipom!!!" And then I paused, and I thought, "Ambipom's riding on the back of a Kingdra, over the seas!" That was awesome!!!
I also saw Banette, and it reminded me of a high school friend (however, that only happened a few days ago, while I had known this person for over a year now).