is practically a Trek convention when it comes to guest-stars. So far, Kate Mulgrew, Jeri Ryan, Rene Aubojonois, Armin Shimmerman, and Brent Spiner have all appeared on the show, often in recurring roles. (I think Shimmerman is the only one who hasn't made a return appearance yet.)
I figure Wil Wheaton and John DeLancie are only a matter of time . . .
loves its Trek-friendly guest stars, too.