-Order of Malta. De Jure recognition, no territory or population to speak of. Basically a forgotten joke country left over from a bygone era.
-Trasnistaria. Has population, land, flag, collects taxes. Only recognized by Russia. There's a few Russian backed puppets like this, I won't name them all.
-Taiwan. Already discussed.
-Hong Kong. Mainland Chinese media calls the protestors terrorists. Yet another example of "terrorist" meaning simply "whoever the establishment wants to de-legitimize". If you follow the CCP narrative, the thing they care about isn't Democracy but separatism. "One China" is about not recognizing Taiwan and HK as a matter of ethno-nationalist principal.
-Palestine. Recognized by majority of UN countries. Still not recognized by US, Israel, and associated power block. Why? Because of the stupid belief that recognition will somehow legitimate it.
-ISIS. At their peak they had a sizeable chunk of land, a flag, a capital, civic functions like a court system, an oil industry, handed out passports, were fighting a conventional land war using conventional (not terrorist/guerilla) tactics, had a uniformed army, and the word "state" was right there in the name. But don't you dare call them a state lest someone mistake you for a terrorist sympathizer.
This is why I subscribe to De Facto nationhood instead. A nation is a nation when it satisfies the following properties:
-A plot of land with well defined borders.
-A permanent population on said land.
-A Monopoly on violence over said land.
-An organization capable of credibly making peace, declaring war, and otherwise accepting agreements with other nations.
The last one is tricky as it only specifies the capability not the actualization. For example, if the organization agrees to peace but the individual factions of the army keep fighting then this condition is not satisfied and what you have is a stateless warlord situation. For another example, the ISIS situation clearly had an organization which was capable of agreeing to a surrender or appointing an ambassador, but they never wanted to or were allowed to. The condition is still satisfied even though they never did it.
That's playing a bit fast and loose with the facts there. ISIS conducted public executions, crucifixions, desecration of cultural sites and enslaved people for a labor force. That's textbook asymmetric warfare/terrorism.
The US has done all of these except crucifixions. Arguably, we've done all of them (except crucifixion) within the last decade. I'm not sure we can claim "not crucifying" as moral high ground when Americans did things like the following (warning: what follows is horrifying):
"He was chained by his neck and dragged out of the county court by observers. He was then paraded through the street, all while being stabbed and beaten, before being held down and castrated. He was then lynched in front of Waco's city hall."
"Over 10,000 spectators, including city officials and police, gathered to watch the attack. There was a celebratory atmosphere among whites at the spectacle murder, and many children attended during their lunch hour. Members of the mob cut off his fingers, and hung him over a bonfire after saturating him with coal oil. He was repeatedly lowered and raised over the fire for about two hours. After the fire was extinguished, his charred torso was dragged through the town and parts of his body were sold as souvenirs. A professional photographer took pictures as the event unfolded, providing rare imagery of a lynching in progress. The pictures were printed and sold as postcards in Waco."[1]
This happened in 1916--most would consider the US to have been a nation for over a century by this point.
[1] https://en.wikipedia.org/wiki/Lynching_of_Jesse_Washington