If you don't have time for a full novel, short stories are a great alternative. Roald Dahl's stories for adults - collected in books like ''Tales of the Unexpected'' - are darkly humorous, brilliantly written and perfect for dipping into while waiting for an appointment or a delayed train.
5. [[Eleanor Oliphant is Completely Fine by Gail Honeyman|'''Eleanor Oliphant Is Completely Fine by Gail Honeyman]]