Kiribati is generally the first country to enter the New Year because its Line Islands use UTC+14, the world's most advanced civil time zone.
The Republic of Kiribati is a Pacific island country spread across a huge area of ocean. In 1995, it moved the International Date Line around its eastern islands so the nation would share the same calendar date. Kiritimati, also called Christmas Island, lies in the Line Islands and is the best-known inhabited place in Kiribati to welcome the new year first.
The answer is sometimes given as New Zealand because the country is prominent in international broadcasts, and the Chatham Islands enter before New Zealand's main islands. However, “first” depends on the location and the date-line rules being used. Kiribati's UTC+14 territory is the standard answer to the country-level trivia question.