Since ancient Greece (and certainly before), some people have complained that the children of today are spoiled, useless, and will destroy the civilization. Sometimes it's true, but I'd say far more often it isn't. Is it really a fallacy to point out that the same claims have been made for over 2,000 years, and yet the world continues to advance and survive somehow? Could it be that (gasp!) people get crotchety and tend to forget what they were like as kids when they get old?
I'll bring up a counter-fallacy, the "rose-tinted glasses" fallacy, in which everything was so much better when you were a kid, and kids these days don't know nothin' 'bout nothin'.
Or the "I call fallacy" fallacy, in which you claim an opponent is committing a fallacy of some sort and hope it sticks.