Boots (they sell appliances on line). I have been very happy with the service and prices, about 100 pounds less than in currys, they deliver in 2 days and take with them the old appliance for a small fee. And you get a lot of points to spend in store
I bought a stainless steel range from UK Appliances online and was really satisfied with the the product and services as I was quite nervous spending that much money on-line but I got it much cheaper than from a shop and I ended up buying a lovely Italian porcelein sink online too - both worked out really well.
www.tradeappliances.co.uk are good. They've also got some big retail outlets in teh East Midlands which have been around for ages so they're not dodgy. They're really good value. There Smeg cookers are 300 quid cheaper than John Lewis.