The Hawkmen skywriting "THANKS FLASH" with their bodies. Dawwwwww...
The 2007 Series
The brief romance between Aura and the dancer, which is possibly the first time in the series that she actually looks happy. And then, Ming kills the poor guy.
The episode "Ascension" has Vultan, leader of the Dactyls, search for decades for his lost son. T.J., the boy in question (who somehow ended up on earth) is a good kid who's hit the rebellious teen years. He gets rescued by the Vultan and the Hawkmen and discovers his heritage. Though he does like his real father T.J. realizes his been hard on his adoptive mother and should go back to earth and set things straight. Vultan, for his part acts as the very supportive father.