Tired of that phrase "jump the shark".

Cartoon: GI JOE THE MOVIE (COBRA-LA)

Toys: 1991 (when vehicles went into the neon toilet and spring launchers and other gimmicks appeared in force, plus the line all but rebooted, Cobra Commander was back, the next year Destro was back with Cobra...weak)

Comics: The Snake-Eyes Trilogy and the Return of Cobra Commander. One linked Baroness to Snake-Eyes, and effectively ruined her character to this day. Cobra Commander should've stayed "dead" (just like the Green Goblin, the Red Skull and countless other popular baddies that were too "great" to leave in the grave.)