For me, it is The Tip.
I have a great friend who hasn't had the financial fortune that I have had in life, but who probably works harder than me at his job. In reality he is a Montana State University lifer fan, but his NFL team is the Niners. He attends all the Bobcat games, and I join him whenever I can. He would never really have the opportunity to attend an NFL game, or spend the money to do so, but it just so happened that his work sent him to Seattle the weekend of Jan 19th 2014.
When he mentioned that he was headed to Seattle, I immediately, bought tickets for both of us in the south end zone, about 5 to 10 rows up, about 10 yards toward the middle of the field from the west sideline. As you can imagine, this gave us a perfect vantage point for the game sealing play.
It was a phenomenal game, leading up to the interception. I broke my glasses, dislocated my jaw, and generally had a blast celebrating the back and forth of the game. My buddy and I took turns razzing each other whenever one team would appear to take the advantage.
The Tip replays in my mind in slow motion. The ball is lobbed in a weird motion, and it looks like it may be up for grabs. Sherman and Crabtree go up and it's either going to be me or my buddy celebrating in fractions of a second. Sherman wins the battle and the ball comes down into Smith's hands.
When Thomas finally gets the message through to Smith to take the knee, my screams of "get down man get down" turn into screams of "WE ARE GOING TO THE SUPER BOWL. WE ARE GOING TO THE SUPER BOWL."
The fact that I got to share that moment with my buddy just makes it the best play ever for me.
If I hadn't personally attended that game with my friend, then I would probably vote for Beast Quake 1
-bsd