Books like Logan's Run

It's the 23rd Century and at age 21... your life is over! Logan-6 has been trained to kill; born and bred from conception to be the best of the best. But his time is short and before his life ends he's got one final mission: Find and destroy Sanctuary, a fabled haven for those that chose to defy the system. But when Logan meets and falls in love with Jessica, he begins to question the very system he swore to protect and soon they're both running for their lives. When Last Day comes, will you lie down and die... or run!