[Shaun]

Just random predictions:

Groups
Hope - Dont'cha, by the Pussycat Dolls.
Same Difference - No idea.

Girls
Alisha - Unfaithful, by Rihanna

Boys
Andy - You Give Me Something, by James Morisson
Leon - Chasing Cars, by Snow Patrol
Rhydian - Patience, Take That

Over 25s
Beverley - Beautiful, by Christina Aguilera
Niki - White Flag, by Dido