Best in Britain?
My go to LBS, either in person or online. The Hampton Wick showroom is like the Apple store for bikes, large, modern and cutting edge. The staff are friendly, helpful and knowledgable. Their website is really easy to use and the click and collect and mail order both reliable with excellent communications as to the status of your order. I always recommend to any of my club mates and friends to go there, some think it is expensive (a misconception based on it's wonderful appearance) but when you drill down and compare their prices with competitors you'll see that they are just as cheap.