Days 20-40 after the shocking death of George O'Malley saw the staff find some measure of closure, as the winds of change began to blow through Seattle.

As Grey's Anatomy turns 100, Meredith and Derek prepare to walk down the aisle as Izzie's condition brings back familiar (handsome!) symptoms. That's when MerDer decide to give their wedding away to Alex and Izzie.

We had a bad feeling from the start in the third season finale, which ended with MerDer's split, Burke's shocking departure and Yang bawling on the floor.

Devastation. The plane crash that took place in the eighth season finale claimed multiple lives and changed others forever.

Picking up in the wake of "Flight," and besieged by offseason rumors and spoilers, "Going, Going, Gone" saw the death of Dr. Mark Sloan (Eric Dane) in a Season 9 opener that was disconsolate at best, jaded and bitter at worst … but certainly memorable.