The first game I played was Gold. I asked myself this question when I played through Blue. Then again when I played through Emerald. And most recently, when I played through Platinum. I imagine I'll wonder the same thing when I play through Black or White.

However, unlike you, I never found an answer. The stories are minimal, basic, and uninteresting. The stat building is stupidly handled. Too many things (catching, breeding, natures) are left up to random chance. There is still a ton of untapped potential in the series, but it'll probably never be realized, especially if the games continue to sell as well as they do.

And yet I play on. Such is the nature of Pokémon.

I don't play Pokemon, so I can't even guess why you play.

When people ask me why I play Pokemon, there are three main reasons:

1) I love RPGs. And you get to pick from now more than 650 Pokemon in that RPG. And they all can be customized with over 30+ moves a piece.

2) What other RPG can you create your own party and battle it out with friends?

3) And with a few other exceptions, how the hell else can I train up a bunch of massive dragons to take over the world?!

I play because it's my default game and fills in gaps when I'm not really in the mood to play anything.

I used to play competitively back when that meant dodgy web-based simulators or sending commands to bots on IRC chats. Once they went to the 3rd gen stat system though, it became too much min-maxing for me to handle when I was working/going to school.

Now I mainly fill the role of a catcher and take the Pokedex-filling part seriously. I intentionally keep 2 DS-capable devices around for self-trading since I want to do it on my own.

When I started to play Pokemon was back at the very beginning when my friend told me "Hey, you should check out this show where these little monsters fight in the morning."

Yes, my friends this was when the show aired at off times like 6am in the morning and the Game had only ever been released as Pocket Monsters in Japan.

My mother bought me Blue and my brother Red.  Which I immediately start to sink time into.  I like pushing the odds.  Developing a relationship with my crew as we trained to be stronger.

My mother from that point through Gold and Silver just pre-ordered the games for me without me even asking.  I spent much time with those game leveling up my crew and having the quirky story.

After that though I have bought some of the later ones but I can't say I've put as much time in all of those combined as Silver.

There just to many Pokemon to be a master of in all the later games with so many Pokemon I also get disheartened to only find like 10 for the first few hours of the game.  The basic catching aspect haven't changed.  Simply put the series really hasn't evolved enough for it to get its hook into me again.

Though I'll leave with this thought.  Why I like the original Pokemon is really the same reason I like this Retroactive with Fire Emblem.

I raise Pokemon competitively, especially once I found how EASY it was to get the desired nature, and stats. But what really keeps me going is sitting through that massive Pokedex and trying to figure out what really unsuspecting creature I can use to wreck havoc among everyone else.

Sometimes I really can't stand the hard core competitive players. If only because of how serious they take everything. I look at those formulas, the calculations and all that jazz and it's just too much. But I generally love using a Pokemon that most people hate or has a design most people can't stand.