The Victorian Web has a list of best selling novels in the years 1862 to 1901.
Margaret Oliphant's The Doctor's Family
Margaret Oliphant's The Last of the Mortimers
Henry Kingsley's Ravenshoe
Ouida's Held in Bondage
Margaret Elizabeth Braddons's Lady Audley's Secret
Bulwer-Lytton's A Strange Story (serialised in AYR) first-person narrative
Harrison Ainsworth's The Lord Mayor of London
Anthony Trollope's Orley Farm
Wilkie Collins's No Name (3 vols).