CSI: New York
TOS had stories written by science fiction writers.
had stories written by criminologists.
Certainly none of the subsequent Star Trek series were more cerebral.
For that matter, none of TOS was quite as cerebral or as dramatically solid as "The Cage," with the possible exception of "Corbomite Maneuver."
Actually, the next time Star Trek pulled out a real dose of deeply thought-provoking science fiction was The Motion Picture. That was also, IMO, the LAST time.
I think I've watched most science fiction series and movies since TOS until the last couple of years we're frankly is mostly magic and vampires
The Man Trap
Who Mourns for Adonais
Wolf in the Fold
Yeah, I've never seen a TOS episode about magic and/or vampires (I mean, unless you think that changing vampires into aliens suddenly makes your story more cerebral