Normally, my favorite episodes of "Star Trek: The Next Generation" are those with are monumental in scope--and are often two-parters involving the Borg or Klingons. However, there are a few standalone episodes that are truly wonderful. They don't relate to any other episodes but they are nonetheless terrific. The best of these, clearly, is "The Inner Light", but another wonderful one, with a VERY different mood, is "Devil's Due".
The episode begins with the Enterprise being brought to a planet after some Federation folks are kidnapped (this is a rather frequent theme, by the way). WHY this occurred is a trip. It seems that the planet's version of the Devil is coming...and in a panic, the people will do anything--even kidnap Federation staff. Picard is a bit annoyed by all this but his annoyance grows exponentially when this devil appears before him and the leader of the planet! This incredibly cool and rather sexy being announces that she's come to collect her due...and her due is the planet as well as anything orbiting it--which includes the Enterprise. What follows is a silly "Devil and Daniel Webster" sort of court case in which Picard tries to invalidate the contract with this 'lady'--but really it's just a delay tactic in order to allow LaForge to seek out the source of this woman's magical and very formidable powers!
So why did I like this episode so much? Well, it's something most episodes of the series never were...FUN. The performance of Marta Dubois as this evil and mythical 'Ardra' was simply delicious. While a bit over-the-top, it was done in such a fun and seductive manner that I was simply captivated by her...and you wonder why Picard didn't just shut up and give his soul to her! Lots of fun and a great change of pace.