Selfridges has been one of my go to stores whenever I am in London. It is amazing to have so many options and brand under one roof. And I particularly like their food hall.
The customer services I have received has always been first class. The staff are always polite and willing to help.
I find their website to be okay, however when shopping in the sale, it often shows items as I stock when they are not, which can be very frustrating. That partnered with the £5 delivery charge is off putting.
However as a whole I find this shop to offer above and beyond and would highly recommend going into store if you live nearby.