I would consider the main Ash shippings to be the pairing of him with his female travel companions. I'm pretty sure that the size of the fanbase for each ship has gone down with each new companion. (pokeshipping is more popular than advanceshipping, which is more popular than pearlshipping, which is more popular than negaishipping.)
Anyone want to comment on why this pattern is happening?
You don't have to stay 100% on topic here. And this is sort of a discussion thread and not completely an "answering this question" thread.