Haha, McGonagal in Big Brother would be hilarious. I like my house to have big drama so I would love celebrities who'd clash. If only Jodie Marsh and Jordan where in that house together.
As far as my line up would go I wouldn't mind a few comedians in here and there. I did enjoy Sov in last years because I like that she spoke her mind. So characters like her would be appreciated in my books!