If you enjoy the Jack Reacher series by Lee Child, then you'll likely appreciate a number of similar books featuring strong male protagonists. Some good series to check out include:
David Baldacci’s Camel Club series: This secret society deals with solving paranormal mysteries and takes on the most powerful people in the land. It stars the determined Oliver Stone and his team of protagonists.
John Sandford’s Prey series: Detective Lucas Davenport is a top police officer in Minneapolis who must battle criminals, victims, and bureaucracy alike.
Robert Crais’s Elvis Cole series: Elvis Cole is a private investigator in Los Angeles who is hired to handle everything from kidnappings to murder cases. He’s a tough but likeable character and his cases are always full of twists and turns.
Michael Connelly’s Harry Bosch series: Bosch is a homicide squad detective in the Los Angeles Police Department. He follows his instincts and finds evidence that others have missed. His cases are filled with suspense and action.
Other great series to check out include Vince Flynn’s Mitch Rapp novels, Grant Blackwood’s Briggs Tanner series, Robert Ellis’s Carl Stanning series, and Stuart Woods’s Stone Barrington novels. If you’re looking for books like the Jack Reacher series, these should suit your taste. Enjoy!