I think last 3 should be:
Brian
Helen and,
Dean.
Bubble is such a manipulator in the way he'll occasionally go to the diary room and blub about his daughter to keep viewers on his side. Narinder is soooooo 2 faced and I don't think the rest will be able to cope with her for much longer. Amma showed her real self on Brian's birthday by completely blowing the argument with Stuart out of poroportion and showing her insecurities. Paul is just too dull to last any longer. Dean and Elizabeth will both last for a long time as they are doing an 'Anna' by, primarily, keeping out of things and not getting in anyone's way.
Personally I think Helen should win, she is the only housemate who is being herself and has come across best so far even if she is a bit dippy!