Bestseller lists are somewhat questionable, to be taken with a grain of salt. One should not rely on them ‘definitively.’ Instead, rely on friends, family, book clubs as your sources of reliable reading references. They are better sources than bestseller lists as you can talk to them to learn more.
Goodreads 2015: www.goodreads.com
Chicago Tribune: www.chicagotribune.com
Globe and Mail: Globe and Mail Bestseller list
Literary Review Canada: reviewcanada.ca bestsellers list
Sunday Times: Sunday Times
Toronto Star: Toronto Star bestsellers list
USA Today: USA Today bestsellers list