Best packaging experience: probably that time I bought two Westinghouse 100w A23 clear lamps from Tim off of LG. They were encased so well in packing material I had to spend a few minutes getting the bulbs out. Everything arrived intact as it should.
Worst: I bought a fairly hard to find
traffic signal off of eBay and it was packaged wrapped in a thin layer of loose fitting foam in a cardboard box. Worst of all the internals of it weren't padded so a reflector came loose during shipping and basically obliterated all the glass reflectors and broke the green lens. The seller refunded me a significant portion of the costs so I ended up keeping the light and restoring to function. It look me years to find a matching green lens for it though.
Here's is how it looks now with a set of correct matching lenses, a new paint job, and replacement gaskets.
Runner up: I bought a Philips SOX 35 last year from Amazon and it was shipped loosely in a large cardboard box. The outer made it but the inner tube was shattered. They sent me a replacement one which was properly padded and that arrived intact.
Here's a picture.