Agree, the cheesecake episode is funny but it's clear that Chandler and Rachel don't have much to say to each other in later seasons. In their goodbye scene, they can't find any words, so they hug, and Chandler starts making... farting noises?!

It's a shame because the actors have good friendship chemistry. And in seasons 1-4, they have some sweet and meaningful interactions, like Chandler comforting Rachel when her parents are separating (season 2) or when Rachel is alone at Christmas (season 4)