I have always loved the Dark Crystal. Some of my fondest memories of my childhood include singing my three-year-old version of the Gelfing song that Kira sings in the boat on the lake. It is a brilliant film: artistic, morally sound, and exciting, inspiring the nescessary terror and pathos to leave the veiwer in a cathartic paralysis that leaves one speachless for ten minutes after the credits have finished rolling.
Here I will wax erudite as to the deep symbolism that one discovers only by watching the film wayyyyy too many times.
The Triangle: A symbol of perfection. The Triangle is associated with two forces merging to become something greater. Each force pushes against the other up to form the apex of the circle, as in the Mystics and Skeksis becoming a single race again after their millenium of separation. This same principle can also apply to marriage: one partner is incomplete without the other - "Nevertheless neither is the aman without the woman, neither the bwoman without the man, in the Lord" (1 Corinthians 11:11), but together they are truly a force to be reckoned with. Jen and Kira were both instrumental in the healing of the Dark Crystal, and although Jen is undoubtably the principle character, all would have been lost if not for Kira. Alone, either would have failed utterly, but together they defeated the ultimate evil.