I am with this company and am very pleased with them, from performance and support - one of the best.

http://www.adsl24.co.uk/forum/

Costs

http://adsl24.co.uk/index.php

Note that you have UK based Support, rolling 1 month contract, no exit fees and no port blocking.

I have Home Braodband Home30 for 19.99 a month. You get what you pay for.

I did a lot of research before switching to this company and they have been great.