Here at Matrix we provide email facilities and of course web hosting, but the vast majority of support calls we get for clients unable to access their email or websites, are down to the ISP providing the broadband access to the internet.
So the question is which provider should you go with? Well I would answer that with a question - how important is your broadband connection? Most if us would say it's quite important, but to really put this into context you need to consider what the impact would be to you or your business if you had no internet connectivity for a few days. For most the thought of no emails, no access to any websites will soon bring them to the conclusion that price may not be the biggest factor.
For the record I personally go with BT, as I figure I can't then be played off between the phone line provider and the service provider in the case of an issue.
Another factor to bear in mind are local factors. If for example one of your main options is a cable company, then any reliability issues may be more localised, so it may be worth checking whether any friends or businesses nearby have had good experiences.
For businesses, you may need to look at special business broadband packages. If you look at the small print for home broadband, you may be breaking the terms by sharing it on your network in the office.
If no internet in the office is not an option, it may be worth considering backing up your regular phone line based broadband with something like cable to give extra resilience.
Here is a breakdown of the biggest providers in the UK currently:-
Broadband connections in Q2
1. BT 4,500,000 (+103,000 customers)
2. Virgin Media 3,836,100 (+54,000)
3. Carphone Warehouse (TalkTalk/AOL) 2,754,000 (+44,000)
4. Tiscali 1,838,000 (-37,000)
5. BSkyB 1,628,000 (+200,000)
6. Orange 1,063,000 (-44,000)
Figures published in the Guardian