That's the title of the first issue of Young Justice, and is also an observation made by someone from Gemworld: Earth has been through seven reality-changing Crises, and the folks of Gemworld are getting fed up with getting smacked by the backlash.
So, what are the Seven Crises?
My guess:
1. The Crisis on Infinite Earths
2. Zero Hour
3. Infinite Crisis
4. Final Crisis
5. Flashpoint
6. DCU Rebirth/Superman Reborn
7. Metal
What do you think?