A Best is the first greatest hits album by Japanese singer-songwriter Ayumi Hamasaki. It was released on March 28, 2001, by Avex Trax and Avex Music Creative Inc. Hamasaki had originally planned to release the greatest hits album after her 2002 studio album I Am..., but the idea was denied by Avex head staff. Instead, Avex released the album in 2001, which caused conflict between the label and Hamasaki. The compilation was released in two different formats including a physical and a digital release. Seven different artworks were released in several editions of the album. The album includes one new track, three re-recorded tracks, and the rest of previously released singles.

Ayumi Hamasaki is a Japanese singer, songwriter, record producer, actress, model, spokesperson, and entrepreneur. By 2002, Hamasaki had earned the nickname "Empress of J-pop" due to her popularity in Japan and throughout Asia, as well as being referred to as "the voice of the lost generation". Due to her success and relevance throughout her career, she is considered one of the top solo female artists of the Heisei era for her influence on the music industry and various fashion trends.