Mine is a bit odd because my favorite Seahawks play ever was accomplished by my least favorite Seahawk ever.
I just think for me, Percy Harvin's return TD to kick off the second half in 48 provided that moment when I knew that the dream had finally been realized. I was 100 percent convinced at that point that it was our day, and nothing was going to stop us from getting that elusive ring. Being a Seattle sports fan for nearly all of my cognitive life, there have been so many disappointments throughout the years. But when that bastard took that kick to the house, I knew it was finished, and I knew all the tears, anger, and disappointment I had as a fan was extinguished and forgotten in that moment. And it's a play that I still love to watch, despite my disdain for the man who did it.
I can't really explain it better than that. When he crossed the goal line at the end of that return, I knew we were SB champs. It was a feeling I hadn't ever had as a sports fan. At that point, Denver was completely deflated and done. I remember telling my wife that if he actually had a chance to return the kick off, the game was over. As soon as he fielded it, I turned my back and looked at her, and smiled as she went crazy. It was the moment it was all realized. 29-0 at that point, and I knew that no one could ever say that we weren't champs again.
Tied for second are The Tip, Beast Quake 1 and 2, and Russell finding Kearse for the game winner in the 2015 NFCCG. I just can't bring myself to ranking those, so they are all tied.