If you enjoy partners in crime (husbands and wives, inspectors and sergeants, coworkers, etc.)
try a few of these titles:

Steve Allen Murder Game
Deb Crombie A Share In Death
J. Evanovich One for the Money
E. George A Great Deliverance
D. Hammett The Thin Man
Caroline Hart Death on Demand
M. Hardwick Malice Domestic
F. Kellerman The Ritual Bath
Susan Kelly Hope Against Hope
C. MacLeod The Gladstone Bag
Anne Perry The Face of a Stranger
Cater Street Hangman
E. Peters Amelia Peabody Series
Dorothy Sayers Busman’s Honeymoon
Kate Wilhelm The Hamlet Trap