I used to be with Tiscali, but they suffered a denial of service attack which meant that nobodys emails were getting delivered or sent, so I had to move quickly to another ISP.
I went for Orange and wished I hadn't. Their support is worse than useless - see this site to read all about it
http://www.orangeproblems.co.uk/phpBB2/
Their phone service is not standard either, it is basically VOIP which means that the quality is not brilliant, and the only way you can access the free calls is by using their wifi router called Livebox.
As soon as my minimum contract is up I shall be looking to change to another ISP.