1. United Kingdom of Great Britain and Northern Ireland. Or U.K. for short.
4 nations (and other dependant territories) comprising one country who all share one currency, one language (mostly), one head of state, one executive parliament, one armed forces, the same passport, the same UN representative, the same combined flag etc.
Great Britain (GB) is the geographic name for the main land mass that comprises England, Scotland and Wales. However, it can be used to represent the U.K. as a whole (the Olympic Games being prime example).
Although to be fair, it all depends on your definition of a country. This is all open to interpretation.
Texas was a country, and some seccesionists may still feel and identity that it still should be.