I live just up the road from The Compete Outdoors and have spent a fair bit of money in there over the years. They stock Paramo, but appart from my Alta coat, I have wound up buying all my other Paramo gear from other places. They are good for a wander around, way better than places like Blacks or Millets, but not exceptional.
The Outdoor Shop in Stoney Stratford is not too far out of my way when I go visit my parents and I have bought some pricy kit there too. They were very helpful, and pretty knowledgable when I was choosing a down sleeping bag.
There is a Cotswolds in St. Albans, not that far from me and I bought my little Vaude tent there, but only because I could get a discount and they had the one I wanted in stock when I wanted it on fairly short notice. They are okay if you have a specific item that you want, and they have it in their range, but they are not the sort of place that I find many surprises.
I was up in Keswick and Ambleside lately and Rathbones in Keswick is pretty good. Very goos staff and some nice gear, well layed out. There were a lot of good shops up there. I had a great time looking at wool gear in the Norwegian Store in Keswick but I think that my favourite place up there has to be The Mountain Factor. They carry Paramo and Icebreaker and OFTEN have sales or offer discounts. While there they also had some huge savings on some Patagonia gear.
Ultimately though, if you take a lifetime's agregate expenditure, I still think that LLBean and Cabelas have done more for me than any of the UK shops. Their service is excellent, they often have interesting things that you won't have seen in local stores. Some prices are often very good and their warrenties make most UK stores look mean by comparison.
