+1 on Plusnet. Used them for years. They are part of BT but have their own UK call centres so you don't have to fight to find someone in the right department who understands what you need. Pretty cheap too, especially compared to BT, I think their TV offering is a little weak compared to BT themselves though if that's important to you.
Also might be worth looking at Sky, I've noticed that their predicted broadband speed is a little faster for ADSL2+ in some areas so might be good if fibre isn't an option.