If you really want out of NTL may I suggest:
http://www.hi-velocity.it
http://www.plus.net
http://www.bulldogdsl.com
http://www.zen.co.uk
I have experience of all bar plus.net.
Zen are the most expensive but their customer service is great and connection is stable. Plusnet customer service not quite up to Zen's standard but stable, and for £40 a month unlimited 2Mbit isn't bad. Bulldog have an occasionally dodgy service but some occasionally great deals, and Hi-Velocity are supplied by Bulldog and others, and offer a much more personal touch with good support and usually stable speed connections.
That's basically what I'd suggest to you. BTBroadband are overpriced; Pipex are good at supplying a basic pipe to the net (most of the time) but decidedly average for server stability and CS is appauling; Fast24 have bad customer service and a fair few complaints about quality of service.
Check out
http://www.adslguide.org.uk for more information on ADSL ISPs it's a site dedicated to ADSL and they actually appreciate that there are DSL ISPs besides Pipex there, which is a bonus.