I have been with Virgin for some time both as a dial up and now ADSL.
I was with NTL but as these do not support ADSL when I changed I went to Virgin broadband.
If your surfing habits don't exceed the 3GB limit then at £18.00 a month is good value and you get 5 email addresses + there is no 12 month contract.
I will say that I have now found out that NTL has bought out Virgin but will continue to use it's name. So far there is no difference in the quality or service given.