[Shaun]

I know they'll pick obvious songs but I think these could work for them:

Abi - "Unforgettable" by Nat King Cole. It's one of my favourite songs, and I hate her, so I shouldn't want this, but I think it would be the ideal song choice for someone like her.
Hannah - "Don't Let Me Be Misunderstood" by Nina Simone. Her voice is dying for some Nina.
Tamera - "My Funny Valentine", the Ella version. Beautiful song, could suit her voice well.

Luke - maybe "The Girl from Ipanema" or "Summer Wind".
Nicholas - "The Quest (The Impossible Dream)" by Andy Williams. Ideal way to prove his vocal credentials, and a great, moving song.
Sam C - "Haven't Met You Yet" by Michael Buble. It's a bit crap and a bit campy so I guess it suits him.

Sam B - "Mad About the Boy" by Dinah Washington... it's quite theatrical, but I dunno if she could stretch it vocally. Maybe "What a Difference a Day Makes" or "Fool That I Am" instead.

Rough Copy - i worry they'll get something cheesy like "Can't Take My Eyes Off of You" but i don't really know what they'd work with