Of all the character deaths on Grey's Anatomy, none came quite as abruptly, shocked fans quite as hard or rocked the series to its core quite like the demise of Dr. Derek Shepherd, a.k.a. McDreamy. "How to Save a Life" marked the end for this iconic character, and rumors of off-set drama involving Patrick Dempsey further intensified the impact of the installment.

We absolutely loved this Derek-centric episode from early in the sixth season. It was one of Patrick Dempsey's best performances and a moving story to boot.

As Mark's chapter closed, this episode flashed back to the time after the plane crash while the doctors waited to be rescued and once they returned home.

With plenty of tension from the parents, Callie and Arizona quickly realized their special day wasn’t turning out as they envisioned. Luckily, it all worked out in the end ... for now.

The sixth season finale stunningly concluded with a madman shooting up the hospital. Nothing would ever be the same at Seattle Grace.