I use Pipex; great service, great speed and for £23 a month for unlimited (one of their selling points is unlimited bandwidth; they've never complained with me) 1mbit dsl it's pretty good.
I use Eclipse. I pay a few quid more per month (£39.99 for a 2mbit business line) than some other ISPs but there's no capping, 8 static IPs if required and I've had less than a days downtime in 2 years with any non-BT problems fixed very quickly. You'll find now with a lot of DSL ISPs you get what you pay for especially since BT changed the wholesale charging models, so don't necessarily be guided by price. But if you can get BY cable, go for that.