On eclipse at the mo as it's only a one month contract. Pay £20/month for 512kb service, but they've just launched a cheaper, faster (2Mb/£14.99) service this month, which could suit fine as long as you're not downloading loads of movies.
Best independent comparison site I know:
http://adslguide.org/ Go to 'Compare Service Providors' and check a few boxes.
Cheers,
Ali