Not exactly quit, but I have lost most of my interest in the series a few times.
The first time was the months before Emerald was released, I had nothing to do on my other 3rd gen games so I didn't play much at all. But I got hooked again as soon as I got Emerald.
The second time was in 4th gen. Once again, I had nothing to do on D/P before the release of Platinum, which lead me to slowly losing my interest. I had hoped to regain it with HG/SS, but these games made me lose my interest even more. It wasn't until B/W that I really got back into the series.