I'm with VM however after them promising me my price would not go up for two years they put it up
When I Argued the toss telling them they are breaking their own T&C's they simply said. You are welcome to leave and we won't charge you a ToC (termination of contract) fee.
I stuck with them because for the speed there is no one else that comes near that I know of
Since then the prices have gone up another 5 times in 3 years. Totaling a 33% increase in my subs per month
Been with TalkTalk since 2009. I think I have only ever had 3 problems in that time. Customer service can be a bit iffy at times because of the language barrier. Bit pricey for the package I have, but hey it does what it says on the tin so I am happy.
I'm using Sky BB and I'm happy with their service. No limits, it's fast, hardware seems decent enough and if you have Sky TV it's often free for a year.