* The King's Singers (UK): The King's Singers are a six-member vocal ensemble that has been performing together for over 50 years. They are known for their versatility, their beautiful sound, and their wide repertoire of music.
* The Mormon Tabernacle Choir (USA): The Mormon Tabernacle Choir is a 360-member choir that is based in Salt Lake City, Utah. They are known for their powerful voices, their inspiring performances, and their weekly broadcasts on television and radio.
* The Westminster Choir (USA): The Westminster Choir is a 120-member choir that is based in Princeton, New Jersey. They are known for their exceptional musicianship, their innovative programming, and their commitment to education.
* The Netherlands Chamber Choir (Netherlands): The Netherlands Chamber Choir is a 20-member choir that is based in Amsterdam. They are known for their pure sound, their expressive interpretations, and their wide-ranging repertoire.
* The Swedish Radio Choir (Sweden): The Swedish Radio Choir is a 60-member choir that is based in Stockholm. They are known for their beautiful sound, their innovative programming, and their commitment to contemporary music.
These are just a few of the many great professional choirs in the world. Each choir has its own unique strengths and weaknesses, and it is up to each individual listener to decide which choir they think is the best.