Last year I decided that sky offered me a better deal than virgin so I cancelled my subscription at the end of the term, virgin then took away my discounts and made sure that I paid full price on everything for my last bill ( surely a 12mth contract is for both of us??) anyway I moved over to sky. my first attempt was using sky+, a move which although had no on demand made me happy, I soon moved up to sky hd when offered a free box off tesco and here I am 12 mths on, watching 4 entertainment packs, sky sports 1 and disney cinemagic ( all on hd) with unlimited broadband and unlimited phone calls with line rental all for £66.00. now they have had excellent customer service because when I have wanted to change over the packages they did it all without any trouble.
if you keep changing packages and keep making calls then you can expect to have different bills every month but go for the unllimited stuff and you cannot go wrong.
They have also told me that we are soon to get on demand tv through the sky anytime service which should cost no more.