Most Memorable Finish in a Race  

1976 Daytona 500.

It was the loudest audience participation event I've ever been a part of as everybody was yelling.  I was 15, and was sitting in row 6, about 50' past the start/line.  The finish was made more dramatic by it looking like Richard Petty had enough momentum to spin through the infield, and make it across the finish line for the win, but his car stopped just short of the line, and he couldn't get it fired up right away.  His crew ran out to push him by hand, and while all of us were watching that, here comes Pearson in the Wood Brother's #21 rumbling out of the infield toward the finish line....

https://www.youtube.com/watch?v=AibV8_0USBA

Locally, the most "memorable finish" (allthough ironically I can't remember who got the win) was around 1983 or 84 at Flemington, it was either a 50 or 100 lapper, and Larry Kline and Frank Cozze crossed the line in what looked like a deadheat.