Country code TLDs

.su

Country code top level domain. It was allocated to Soviet Union and preserved even after the country stopped existing.

.рф

IDN country code top level domain. Allocated to Russian Federation according to its international country code.

.ru

Country code top level domain. Allocated to Russian Federation according to its international country code.

.ua

Country code top level domain, allocated to Ukraine. In order to register a domain you need to have a trademark registered in Ukraine.

.ws

Country code top level domain, allocated to Samoa according to its ISO code. Initially it was an abbreviation of Western Samoa, the official country name in 1970s when the country codes were standartized. This domain is widely marketed as a shortening for website.

.us

Country code top level domain allocated to the United States of America. Registration is open to U.S. citizens and government structures as well as companies registered in the U.S. or having there a dedicated subdivision.

.pw

Country code top level domain allocated for Palau. Became popular as a shortening of Professional Web.

.eu

Country code top level domain allocated for European Union. Registrant has to provide the administrator's address in one of European Union countries in order to complete the registration.

.co

Country code top level domain, allocated to Columbia. Became popular all over the world as an alternative to  .com. For that reason it is widely recognized by different entities including Google as a generic domain.