Simular Artists to Adele

Amy Jade Winehouse (born 14 September 1983 in Southgate, London, died 23 July 2011 in Camden, London) was an English singer and composer, known for her eclectic mix of various musical genres including soul, jazz, rock 'n' roll and Rhythm and Blues.

 Robyn Rihanna Fenty (born February 20, 1988), known by her stage name, Rihanna, is a Bajan singer. Her song Umbrella was one of the highest-selling songs of 2007 and her 3rd album Good Girl Gone Bad was critically acclaimed, helping propel her to superstar status

Katy Perry (born Katheryn Elizabeth Hudson on 25 October 1984) is a singer/songwriter from Santa Barbara, California, United States. Since the release of her 2007 debut single "Ur So Gay", Perry has released two albums - 2008's "One of the Boys" and 2010's "Teenage Dream" - and has had six Billboard Hot 100 #1 hit singles.

                                           

 Jessie J is a pseudonym of, at least, two artists: 1. A singer songwriter from the United Kingdom 2. A rapper from the United States

                                           

There are several artists who go by the name “Duffy”. The most notable of these is Welsh singer-songwriter Duffy (born Aimée Ann Duffy ).                                           

Florence + the Machine formed in 2007 in London, England, United Kingdom. The band is the recording name of singer/songwriter Florence Welch and a collaboration of other artists who provide backing music for her; Florence Welch is the band's only constant member.                                           

All these are from: http://www.last.fm/music/Adele/+similar