Singers:
Robbie Williams
Brooke Fraser (NZ singer)
Dido
David Gray
Bic Runga (NZ)
Norah Jones
Usher
Natasha Beddingfield (NZ)

Bands:
Zed (NZ group)
Lifehouse
Outkast
Bee Gees (yes!)
Pacifier/Shihad (NZ)
Black Eyed Peas
Linkin Park
Steriogram (NZ)
48 May (NZ)
Jet
Franz Ferdinand

I think that's all I can think of for now! There are heaps of individual songs that I like but don't know who sings them.