I'm going to give ntl marks for flexibility (and friendly scottish girls in their call centre).
Called up last week to ask about their 5p phone package, which I found on uswitch. Was told it's not really available any more but (as it's you) we can let you have it.
Called up today to drop my BB from 4Mb to 2Mb (24.99 to 17.99). Not for performance issues, just wanted to save the pennies. The ntl girl wondered aloud if there were any discounts I might be benefiting from, spent a few seconds rummaging through her drawer of Special Offers, and then offered me 2Mb at 9.99 for 6 months.
I've seen others on here get similar deals and people have pointed out the downside, that ntl should be more consistent, but just thought I'd highlight the upside.