1) Obviously when our main man, McDreamy aka Dr. Derek Shepard died. Our lives will NEVER be the same.
2) The plane crash. Mark and Lexie’s unfortunate ending that also ended with Arizona losing a leg and PTSD for the whole lot of them. Can these folks catch a break?
3) When a patient attacked Meredith and the whole Grey’s squad came to the rescue.
4) When a train crashed and impaled two strangers causing the doctors to pick who to save.
5) When the two sisters get in a car accident and the older sister dies.
6) When Denny died and Izzie falls apart.
7) When Jackson and April’s baby dies in their arms.
8) The shooting, enough said.
9) When Christina has to operate on Teddy’s husband and he dies. To make the whole situation even worst, Christina has to go be normal in the OR with Teddy after the whole ordeal.
10) When George gets hit by a freaking bus.
11) When Meredith almost dies from drowning and Derek saves her.
12) When the Twisted Sisters are broken apart.