I'll do it for all the people I have in gold/orange in my signature.
Adam: None
Ashlee: None
Bey: A few from her debut, 2 or 3 from B'Day, none from her two latest ones.
Britney: I believe None
Cee Lo: Solo.. none, in Gnarls Barkley.. a TON.
Chris Brown: Plenty from his debut, a few from Exclusive. The others, none.
Fergie: Solo.. 2 or 3.
Glee Cast: I think I only have 3 covers, and no original songs, that I don't like from them.
Jason Derulo: None
Jessie J: None
Katy: None
Ke$ha: 'Animal (Billboard Remix)'... if that counts. The remix just ruins it. Other than that, none.
LADY GAGA: None, none, and none.
Leona: the majority of the second half of Spirit
Echo is a masterpiece though.
LMFAO: 'Leavin U 4 The Groove' from their debut, that's it.
Maroon 5: About half of their debut.
My Chemical Romance: 2 or 3 songs from their debut
Nicole Scherzinger: None
P!nk: Her whole debut album
Rihanna: Most of her first two albums.
Also I despise 'Man Down' with a passion.
Spice Girls: 2 or 3 songs from their second album (but haven't listened to their final album yet.)
Taio Cruz: None
Taylor Swift: None (but haven't listened to her debut yet.)