| 1920 | |
| 1921 | |
| 1922 | |
| 1923 | |
| 1924 | Poirot Investigates – Agatha Christie |
| 1925 | |
| 1926 | Metropolis – Thea von Harbou |
| 1927 | The Big Four – Agatha Christie |
| 1928 | |
| 1929 | Partners in Crime – Agatha Christie |
| 1930 | Murder at the Vicarage – Agatha Christie |
| 1931 | |
| 1932 | |
| 1933 | The Hound of Death – Agatha Christie |
| 1934 | Parker Pyne, Detective – Agatha Christie |
| 1935 | |
| 1936 | Cards on the Table – Agatha Christie |
| 1937 | Death on the Nile – Agatha Christie |
| 1938 | |
| 1939 | And Then There Were None – Agatha Christie |
| 1940 | |
| 1941 | |
| 1942 | Five Little Pigs – Agatha Christie |
| 1943 | |
| 1944 | |
| 1945 | |
| 1946 | |
| 1947 | |
| 1948 | Witness for the Prosecution and Other Stories – Agatha Christie |
| 1949 | One, Two, Buckle My Shoe – Agatha Christie |
| 1950 | |
| 1951 | |
| 1952 | |
| 1953 | |
| 1954 | |
| 1955 | |
| 1956 | |
| 1957 | |
| 1958 | |
| 1959 | A Raisin in the Sun – Lorraine Hansberry |
| 1960 | |
| 1961 | Stranger in a Strange Land – Robert Heinlein |
| 1962 | Something Wicked This Way Comes – Ray Bradbury |
| 1963 | |
| 1964 | A Caribbean Mystery – Agatha Christie |
| 1965 | |
| 1966 | |
| 1967 | Restoree – Anne McCaffery |
| 1968 | |
| 1969 | Alexander and the Magical Mouse – Martha Sanders |
| 1970 | |
| 1971 | |
| 1972 | |
| 1973 | |
| 1974 | |
| 1975 | |
| 1976 | |
| 1977 | |
| 1978 | |
| 1979 | |
| 1980 | |
| 1981 | |
| 1982 | |
| 1983 | Alanna: The First Adventure – Tamara Pierce |
| 1984 | In the Hands of the Goddess – Tamara Pierce |
| 1985 | Miss Marple: The Complete Short Stories – Agatha Christie |
| 1986 | The Woman Who Rides Like a Man – Tamara Pierce |
| 1987 | Beloved – Toni Morrison |
| 1988 | Lioness Rampant – Tamara Pierce |
| 1989 | Ghost in the Shell – Masamune Shirow |
| 1990 | Postmortem – Patricia Cornwell |
| 1991 | By the Sword – Mercedes Lackey |
| 1992 | Wild Magic – Tamara Pierce |
| 1993 | Wolf-Speaker – Tamara Pierce |
| 1994 | A Poetry Handbook – Mary Oliver |
| 1995 | Emperor’s Mage – Tamara Pierce |
| 1996 | The Realms of the Gods – Tamara Pierce |
| 1997 | Ceremony in Death – JD Robb |
| 1998 | Holiday in Death – JD Robb |
| 1999 | First Test – Tamara Pierce |
| 2000 | Page – Tamara Pierce |
| 2001 | Blindsighted – Karen Slaughter |
| 2002 | Reunion in Death – JD Robb |
| 2003 | Trickster’s Choice – Tamara Pierce |
| 2004 | Whisky Sour – JA Konrath |
| 2005 | Survivor in Death – JD Robb |
| 2006 | Terrier – Tamara Pierce |
| 2007 | The Face of Death – Cody McFadyen |
| 2008 | The Hunger Games – Suzanne Collins |
| 2009 | Bloodhound – Tamara Pierce |
| 2010 | Fantasy in Death – JD Robb |
| 2011 | Mastiff – Tamara Pierce |
| 2012 | The Line Between Here and Gone – Andrea Kane |
| 2013 | Fear the Light: Who Murdered Dracula? – William Massa |
| 2014 | The Winter Long – Seanan McGuire |
| 2015 | The Silence that Speaks – Andrea Kane |
| 2016 | The Murder that Never Was – Andrea Kane |
| 2017 | A Face to Die For – Andrea Kane |
| 2018 | Night and Silence – Seanan McGuire |
| 2019 | The Unkindest Tide – Seanan McGuire |
| 2020 | No Stone Unturned – Andrea Kane |
| 2021 | When Sorrows Come – Seanan McGuire |
| 2022 | Desperation in Death – JD Robb |
Category: Open Challenges