We're with o2 for just broadband.
It was £7.50 for up to 8meg for us, which when we joined up about a year ago was a really good price.
you get a discount if you already have an o2 mobile, even if you're just a pay as you go customer, like I am, so it was only £7.50 a month, rather than £12.50 or something like that.
Been pretty good connection wise. can't comment on their home phone package though!