Performed by: John DeLancie
Appeared in: Star Trek: The Next Generation, Star Trek: Deep Space Nine, Star Trek: Voyager
This is the only non-negotiable, must-have supporting character on this list. Q, the cosmic being who put humanity on trial in Star Trek: The Next Generation’s series premiere, also appeared in the series finale, where he became an ally and helped Picard save humanity.
His last words to Picard were telling: “I’ll be watching. And if you’re very lucky I’ll drop by to say hello from time to time. See you out there.”
No one was more of a challenge and a hilarious pain in the ass to Picard as Q; this is the same guy who transformed Picard and his senior crew into Robin Hood and his Merry Men. We need his irreverence and feigned indifference on Star Trek: Picard, more than anything.