-On Air Pacific NAN-LAX, I met my (uh, ex-) girlfriend
-With NH KIX-HKG, some guy attending the HK part of the Canton fair let me use his ticket to pay a visit
-After a Sriwijaya Air MES-BTJ leg, a local Acehnese-Chinese woman gave me a tour of Banda Aceh
-A few years ago on a cheap DTW-HND, I led a fellow FTer around Tokyo all-night
There are more, but these come to mind first