I've been to Claridge's three times, not for afternoon tea but for lunch when Gordon Ramsay's was there. It wasn't dear at all - about £30 for 3 courses! - and it was just a wonderful experience, not at all pretentious. The lady in charge of the loos dried off our coats, brollies and shopping while we ate, and we had a long chat with her - she said she loved working there and the staff were all part of a big happy family
. And when my friend asked the water waiter (yes, really!) for tap, he started off by saying "I'm terribly sorry, Madame...". We thought he was going to refuse us, but he continued "I'm afraid I can't serve you any of your delicious Yorkshire tap water, but I'm sure I can find you an excellent London vintage".
Have a great time, tanith.