My experience with
Web Hosting UK was not the best at the start. Unfortunately the server installed had something wrong with it (kept crashing for no reason) and so I had to wait for a new server.
However, ever since (now we have stable hardware) the server has been perfect. Speed is right up there with some of the big players and I've had no downtime at all (touch wood!).
Support always answer on the chat system very quickly, and I like the fact you have online chat, MSN, telephone etc as different ways to contact support.
Support will also go out of their way to help you, which is nice to know.
I also have a server with UKFast (which I pay a LOT more for) and there is little difference between the service provided. Main differences are English speaking telephone support (answer within 3 rings) and superior backup solutions.
I would (and are) recommending WebhostingUK as they are the best value UK hosting available IMHO.