Was obsessed back in 96-98 when it was fresh. Had all three of the original versions of the game, then just got one of the future ones.
I watched all of the Kanto and Orange Islands anime, but got sick of it during Johto when every episode had "You did a good job, we're such good friends Pikachu" moments. The show entirely lost what little edge it had.
Read some of Pokemon Adventures (the manga). It's pretty good.
I collected cards, and had the entire Base-Fossil sets. Lost interest around the time the Neo expansion came.
I started playing online in IRC during the 2nd Gen era, played on Netbattle, just a little on shoddy and haven't done much since, though I occasionally read Smogon and laugh at casuals crying about bans. I know the game is deeper now, but it's... too complex, with way too many options and ways to tweak instead of an emphasis on balancing the vast number of monsters. I know there's no way they can all be viable, but it just feels too bloated now. I can't keep it straight in my head anymore, and I prefer RPGs with more interesting battle mechanics anyway. That said, I still play one version of the games as they come. Black and White are definitely the best in the series, and I'm at least pleased Game Freak has continued to improve the games, which is more than can be said for most Nintendo series.