I'd advise Sky - definately if you have a sky subscription for the TV. I think you get phone calls for free from home and broadband speed of 2meg - 16 meg. If you have Sky TV package then the internet price turns out cheap. Another positive is that the call centres are based in Scotland so its just a bit easier to understand the support people (unlike most internet providers who seem to be based in India).
You also get unlimited downloads, sky player on computer and if you want sky+ HD you can get a discount.