My favorite commuter reading is Robert B. Parker's Spenser books. I just finished "Now and Then" which is his latest to come out in paperback. The Spenser stories feature an industrious, tough, moral, intelligent private detective (Spenser) who is never called by his first name.
Parker also writes novels featuring two other detectives, Jesse Stone, a former LA cop now the chief of a small town Massachusetts police department, and Sunny Randall, also a small town officer.
The books are real page turners, peopled with characters you wish were on your side, like Spenser's sometime associate Hawk, the coolest guy to ever appear in fiction, or Vinnie, who can shoot bad guys while he's eating dinner.
If you like private eye novels on the model of Philip Marlow, with a touch of Mickey Spillane, you will like the Spenser books, there are many in paperback and in libraries, and I recommend them to you as great page turners.