William O. or “Billy” Campbell—not to be confused with the late William “Trelane/Koloth” Campbell—was but 29 when he appeared as the title character in TNG’s “The Outrageous Okona.”  No stranger to the TNG producers, he had actually been runner-up to Jonathan Frakes for the role of Riker during the series’ original casting.

Campbell, a native of Charlottesville, Va., soon after starred in Disney’s art-deco cult classic film The Rocketeer. But it would be as divorcee Rick Sammler in ABC's Now and Again—which netted him a Golden Globe nomination for Best Actor in a Dramatic Series—and later as Jordan Collier in SyFy’s The 4400 that he would gain even more fans. He has most reently appeared as Darren Richmond on the AMC drama The Killing.