In the world of Beechcraft step-ups, pilots might start in a Bonanza, move to the Baron and for those not ready for a King Air, consider the Duke.
Far from inexpensive ownership, the right Dukes (ones with good upkeep and upgrades) can be good airplanes that serve serious, all-weather traveling. Up a few more notches is a turbine-converted Duke. Of course, like any high-end pressurized cabin-class piston twin, get an insurance quote before shopping and bring your A-game when flying it home.