I've usually found Australian customs to be fairly friendly whenever I've been returning home - though these days they make me use the automated passport gates so I don't talk to them at all...
Upon arriving in Finland the passport control officer even welcomed me in my native tounge (Swedish). If come through passport control in the nordic countries I can guarantee they will be friendly.
You should visit New Zealand one day, they have very strict rules about bringing anything in, but I've found their customs people to be the most friendly, even shared a few jokes and tips on snowboard gear with one of the officers while passing through the nothing to declare line last winter.
i had pretty good experiences in Philippines or Malaysia, i would say at least third of immigration officers i met at various borders were friendly. from Europe recently we had very nice Polish woman officer who was very welcoming to our family with small child in EU passports queue despite my wife not being from EU
worst experiences were probably Austrian Nazi guys investigating repeatedly my wife's passport, while at other border with Hungary they let freely roam across Europe thousands of illegal immigrants