Each of the following suppliers has particular strengths, so can be recommended for different reasons:
Waterstones is present on the high street in many UK towns and cities. One method of getting free delivery is to order online and collect from a nearby store.
The Book Depository----delivery - which countries?
Foyles is also strong on travel books, though it has long competed in that area with the nearby Stanfords London 12-14 Long Acre, Covent Garden, WC2E 9LP, which specialises in maps and travel guides.
For many decades, Foyles has also been a supplier of sheet music, especially classical music. The main shop's proximity to the famous Ronnie Scott's Jazz Club probably accounts for a healthy Jazz Section. Together with Collets Bookshop, which was situated next door (129-131 Charing Cross Road) from the 1970's, Foyles served the folk & blues market as well as jazz musicians.
The number of folk clubs within a short distance from Charing Cross Road marked the hey-day of that genre. Legendary ones included The Ballads & Blues Club (founded in the mid-1950's and later to become The Singers Club - venues included The Princess Louise Pub in High Holborn and The Bull & Mouth in Bloomsbury Way). Also, Les Cousins met in Greek Street in nearby Soho, and Bunjies Coffee House and Folk Cellar was situated just off Charing Cross Road (at 27 Litchfield Street) from 1953 to 1999.