I bought into the Tiscali service for me ol' mum (The Silver Surfer) who's been using it for the last year and a half problem free. They upgraded the service recently (bandwidth) and reduced the monthly charge (!!). Don't see that very often. I've got the Telewest broadband service which is equally as good.
check this site out as well if you've still got questions :
http://www.whatbroadband.co.uk/ Hope this helps.
Jiminy