How about them singing with thier own mentors?

Craig or Marcus - Gary
Janet, Misha or Amelia - Kelly
Little Mix - Tulisa

Would add a new twist don't you think?

I would clear my bank account voting just to see that Joking aside though I think it would be a massive step forward if two good looking openly gay guys could do a duet on a show like this.

Sorry for the typo: meant to say with their own mentors!

Joe & George Michael?

Joe wasn't openly gay at the time though, or was he?

Misha - Grenade with Bruno Mars (Bruno's not too obvious himself,only as a pairing with Marcus)
Janet - Maybe Broken Strings with James Morrison, or if she did sing with Adam Levine they could do Never See Your Face Again.(Either could potentially work well, can't remember who I suggested to aing with Janet last time I responded to this kind of thread!)
Amelia - Forget You with Ceelo Green (Less Stars In Their Eyes pick for her, as she's not ready to live up to Kelly Clarkson or Pink yet, this song is everywhere too, so I thought I'd better include it! It was my original choice for Marcus's duet, when I had No Air down for The Risk, but I think Amelia could pull it off!)
Craig - Warwick Avenue with Duffy (Suitable alternative to poorly Adele)
Marcus - No Air with Jordin Sparks. (I'll mention her until the show eventually gives into the pressure! Could they all perform their duets with her?)
Little Mix - Nobody's Perfect with Jessie J (Suits their style and their story)