I won't say they're the best but I have found that Claranet give good value for money. Their dial-up is pretty quick. I have found that their support people know what they are talking about and work hard to resolve problems, all for the price of a local call, even if you do have to wait in a queue at times.
On the downside, I have found that they have slowed down their throughput - tends to stop for a while then start again, which I can only put down to the fact that their bandwidth may be under strain - we're going broadband in the near future - but anythings got to be better than Freeserve.
A word of warning - you may find Freeserve hard to shake off on the PC. If you can stretch to it, I would suggest a re-installation of Windows if it remains a problem.