1. That time Addison showed up and crushed Meredith and Derek's bliss
2. Or when Meredith confronted her father about walking out on her as a child.
3. And then there was the time Denny died an hour after he proposed to Izzie.
4. And of course, when Meredith confessed her love for Derek.
5. Then there was that time Cristina had an ectopic pregnancy.
6. Oh god... the homemade bomb.
7. And, of course, when Burke left Cristina at the altar.
8. Remember when Thatcher SLAPPED Meredith?
9.And that time Mer's mom finally accepted her?
10. And that time Derek had a total breakdown in the woods and took it out on Mer?
11. And when Alex got shot?
12. And then there was the time Jackson pulled a little girl from a bus in a storm the second it exploded.