Personally I was a complete Pokemaniac for most of Gen I, but I was disappointed in Gold/Silver/Crystal. Gen III restored my faith in the series (I think I played Ruby and Sapphire almost as much as I played Red and Yellow, and Colosseum got plenty of playtime as well), but by the time Diamond & Pearl came out I really felt the series was getting stale, and dropped Diamond after the first 2 badges. I still got Pokemon Black a few months after it came out because a lot of people had been saying it felt "fresher" than past Pokemon games, and I did enjoy it a lot more than Diamond, but then I stopped playing after the first 6 badges and the game ended up relegated to the backlog.
When the sequels were announced I got the urge to finally finish Pokemon Black, but it was only after discovering Smogon that I begun to think about returning to the series as a whole; reading the profiles of my old favorites like Zapdos, Mewtwo and Metagross was not only nostalgic, but reading their profile entries for the various generations really opened my eyes to just how much had changed over the years, and how many minor innovations and improvements eventually added up to something significant. I started watching some competitive battle videos on YouTube and soon thereafter I started a new file not on Pokemon Black, but on Diamond, wanting to give Gen IV another chance. I ended up really enjoying Diamond this time around, and moved on to Pokemon Black, then Pokemon XD, then Pokemon Platinum, Black 2 and most recently Soul Silver. Pokemon X/Y is currently my most eagerly anticipated 3DS game for the year.
i've been quickly losing interest after playing gen 3 games like ruby, emerald, and xd (loved them to death, gen 4 seemed much less interesting in comparison) i "quit" pokemon after plat and my love was rekindled after playing hgss past year looking forward to playing white 2 and y