Looking at the various nation's rations, beyond the dog's dinner appearance of certain dishes laid out on a stark white plate, it strikes me that I could get along quite well on any of them. I'm not sure about the tuna pate (Norway), and kimchi (Korea) is always questionable until determined well or foul by taste, but I've cooked up and eaten worse.
There are some oddities. The US ration seems to be the only one that includes toilet paper. Single-use toothbrushes, three, in each Italian ration. The "sponge" in the Danish kit looks suspiciously like a green nylon scrubber and I'm not sure how it fits in.
It also strikes me as odd that most of the rations come with matches. There are precious few military uses for matches and fewer people smoke. Matches seem like an atavism when a miniature Bic ($.75) would keep you in lights for a month assuming a pack-a-day habit.
That said I really do like the 'lifeboat' style matches that come in the British ration. If you're going to go to the trouble of packing matches make them good ones.
I also like the plastic cylinder, looks like a miniature match safe, that comes with the Australians ration. Looks like quite a useful object. Perfect for medications, needles and a little thread, or other small objects. Stuff a couple of hooks and split-shot inside and wind the outside with line and you have a little fishing kit for recreation or survival where fish are a sure thing. Make a fishing kit small and light enough in a compliant environment and it might be worth it.