Dang, M09 was pretty much the closest Pokemon has ever gotten (and probably ever will get) to two main characters loving each other, save for Pokemon Live, which isn't considered canon and most PokeShippers don't even bring it up. One page ago, I asked what the AdvanceShipping song would be. But the truth is, AS didn't really get a song. It got a whole movie, in which Ash and May swam with Luvdisc, which is explicitly stated in the games as being a sign that two people love each other. Not only that, but Ash is recognized*as having the closest bond with May, something amazing because her own brother, whom it is clearly stated multiple times that they love each other very much, is right there with them, meaning Ash and May have a closer bond than Max and May do.
All of this leads up to what would be called a bittersweet finish at best and a real kick in the nuts at worst, as we are reminded in Together We Make a Promise that this was the last of the Advanced Generation and Ash and May would be leaving each other. Ash leaves for Sinnoh with Brock, Pikachu and Aipom, May leaves for Johto with Drew, Harley and her team. The two will not meet again except for 3 episodes in Diamond & Pearl. Together We Make a Promise tells us not to lose hope, and we are treated with a scene in Sinnoh that shows us how much Ash and May meant to each other, as the two kept each of their respective halves of the Terracotta ribbon they won together, and both tell of how many times just looking at it has given them the confidence boost they need to win.
During the time they spent in Sinnoh together, May gave Ash a wooden Teddursa as a gift. It is clear that Ash cherishes this gift, as we see at the beginning of Best Wishes that he gives it the honor of sitting on the same shelf as the trophy he got for winning the Orange Islands league, the highest award he has ever received. No other items clearly identifiable sit on that shelf.
I guess you can call that a sampling. I'll right a paper on AdvanceShipping if you guys want.