If you’d like, share that one card you especially treasure, as the only one from a particular country - maybe a country you once visited, or that is on your bucket list? For me, it is this one from Israel - obtained via a swap. It is of the Banias Nature Reserve.
I briefly visited Israel when I was in my late 20s - had fun in the resort town of Eilat, before going on down to Sharm el Sheikh (Egypt) to catch a scuba diving boat.
I’m just starting so most of my countries are just 1 postcard! But the one I would love to get and still haven’t, is by far Switzerland 
my favourite country (with Germany! But Germany is really active in postcrossing and most of mine come from Germany already 
)
I’ve had a few:
In fact there are more than I expected - there are 20 more!
Postcards I received from rare countries that I posted in another topic. Other than that :
Private swaps :
New Zealand
Puerto Rico
Official :
If you have ANY from South Africa, it would probably be worth keeping them for their rarity value: you are unlikely to get any more from here. Our postal service seems finally to have collapsed completely.
My one and only card from Brunei, and yes, I’d love to visit there one day!
Interested in hearing what are the rarest of postcards – that of only one received postcard from a particular nation. Both were received through regular Postcrossing activity.
Glad to receive one from Chile, especially Rapa Nui (Easter Island).
https://www.postcrossing.com/postcards/CL-28533
Looking forward to receiving more postcards that represents this nation’s rich archaeological heritage, but this one will suffice for sure.
https://www.postcrossing.com/postcards/GR-85479
P.S. @Errol42, I have been fortunate enough to receive two postcards from South Africa.
Hi mezzanine2, that’s good news! Thanks for letting me know. It would be even better if they’re recent ones.
I think there are a few.
Bermuda:
Cyprus:
Denmark:
Estonia:
French Guiana:
French Polynesia:
Greece:
Philippines:
Romania:
I hadn’t realised how many special and “rarer” countries I’d received from. There are still many more to go…
Right now it’s a dozen countries that I have only received one official card from, but I am still just hovering under 200 received.
I always get happy/excited to either send or receive a card from a “rare” country, because the scarcity makes it special.
AND
I always get happy/excited to send or receive a card from one of the “big 3” that I get a lot, because there are some very experienced and brilliant Postcrossers in those countries, and their cards often give me great new ideas for improving my outgoing cards; also when I send to them, I feel like I have a better chance of the card not expiring.
So there are happy thoughts when I draw your address, no matter where you live. 
I am so sad to hear that - I hope it turns around for the better!
Iceland. I received the card five years ago, and the sender, @Eirik31, is still an active Postcrosser. According to his profile, he speaks nine languages. This is why we here in America typically speak only one language; the Europeans are hoarding them all.
A lot of postcards that are from more “rare” countries I have only one of, here are a few of those!
Argentina
French Polynesia
Uganda
Togo
Falkland Islands
There are 33 countries from where I have received only one official card. Yemen, Turkmenistan, Solomon Islands, New Caledonia, Mongolia, Lebanon, Kuwait, Kyrgyzstan, Jordan, El Salvador…
Aland Islands, Greece, South Korea, Luxembourg, Moldova, Norway, Panama, Singapore, Spain and Turkey
My list surprised me! Official postcard wise these are my 1 postcard countries:
Gordon! I’ve had a card from him too.
From Saint Pierre & Miquelon - one of my favorites!
Quite a few! For officials those are:
Wow! Some gorgeous cards there. Moldova looks like the “land of fairy tales” - awesome castle! Thanks for sharing these.
