It really has changed considerably as the show's progressed.
Initially I liked:-
Pauline - (for 24 hours)
Kimberley - whom I then began to loathe for being cold, aloof, boring and for abandoning Ashleigh and Danielle in favour of bully Helen and her posse of cowards...and of course for her disgusting behaviour with Steven.
Matthew - Until he became a spiteful, b*tchy little gossip.
Christopher - Seemed ok at first but then I found him boring as hell with his constant twittering and navel-gazing making him resemble a middle-aged woman. However he's starting to show some gumption lately and is less of a doormat to the manipulative Mark.
Chris - I really liked him early on, but he's proven himself to be weak, cowardly and far more boring than I expected and I detest the way he creeps and snivels up to Helen whom he seems to detest, but has never had the courage to stand up to.
Zoe - for being positive, sociable, likeable but almost too good to be true, and I didn't like her comment about not being able to relate to 'normal' people.
Ashleigh - Whom I have always liked, she's been the only consistent one in the house and has a wise head on young shoulders.
Ashleigh to win.