I think the halcyon days of such gifts are in the past, except on a few carriers like KLM where they continue their tradition of miniature Bols-filled Delft houses. AC in First Class [when it had such a thing] gave out quality art reproductions of The Group of Seven, a famous genre of Canadian paintings from the 20s and 30s. Before these items, there were small porceline containers of maple syrup, quality leather business card cases, and annual Letts diaries.
A couple of years ago, I was flying CX over the Chinese New Year period and on a New Year's Day J-class flight to Sri Lanka, received [somewhat ironically] a beautiful tin of ceremonial Chinese Tea.
We now have tohope for at least a usefull after-flight case from the amenity kits provided in J and F classes. But even these cases have gone into decline on many carriers, as has their contents. I still use some of my quality leather ones from the old days of AC and CP first class. They only have upgraded business class now on international services. I use each of these to hold my Walkman, DV video camera, PowerBook connector cables/power charger, and my own custom packed/filled in-flight amenities kit.
BA's First cases are very practical for storing all sorts of little valuable items, from jewelry to my portable audio mixer/mikes/transmitter kit. Most others I have recently come across have pretty limited reuse potential unless they've been designed specifically as such: CD cases [several carriers], fine leather pouch/bum packs (LH and Air NewZealand], real toiletry kits [LH and CX).
In sleeper first class on many carriers now, PJs of some fashion are regular features, as are robes and slippers on JL. I now have a collection of such garb, and seldom lack for a workout outfit or sauna clothing.
I suppose the Concorde is another place where one still receives such gifts, as well as a commemorative flight certificate. I have one dating back to the days when AF continued their Washington flight onward [subsonically] as an all First Class Braniff dinner flight to Houston. It feature enhanced menus and fine wines, as well as leaving the sense of achievement that one had flown the fastest and most expensive plane in the world, even if we were cheating a bit.