I really like Goodge Street and would never go anywhere else. The standards haven't been as high as usual recently, but I've still found that the technicians are much better than anywhere else I've tried!
Splash Goodge Street never fails to impress, by far the best Shellac I have in London. It always lasts two weeks without chipping, the salon is in a good location and you can have a glass of Processo while getting your nails done!