I vividly remember the first time I heard about Pokemon. I literally went to bed one night on a perfectly normal day, and the next day, I woke up and everyone was talking about this thing. It was kinda weird. This was over a decade ago, and I hear the show is still alive and well. Remember the original opening theme? Remember when we thought Mew-2 was the baddest Pokemon around?
REMEMBER WHEN THERE WERE ONLY 150?!!!! How many are there now? Gotta catch 'em all? HA, good luck!
At what point does a series run for so long that maybe it becomes time to give it an honorable discharge? It all comes back to profitability. Shows like Pokemon, One Piece, and Naruto are such bottomless wells of money in many ways other than TV, it will almost be ill-advised to cut them off after 200 or so episodes. Why stop when there are so many Nintendo games to be made? So many playing cards to be sold?
I prefer my anime shorter. I typically max out at around 46 or so, like with most of the Gundam series. I find that the shorter a series is, the more coherent the story is, in return making for a better show. Case in point, Read or Die, Bakemonogatari, Death Note, Infinite Ryvius to name a few. When a show runs on and on with no end in sight, I feel like it eventually has to run out of track, like a train that...well....runs out of track!
Bear in mind that this is only my opinion, and I'm sure there is something to like in a show that's 200+ episodes long. Maybe someone out there can explain it to me? In closing I would like to make a recommendation for Bakemonogatari. If you are looking for a show that is modern, deep, and won't waste your time, look no further. If you've already seen it, do let us know what you thought.