My humble vote goes to The Beast.
I am a big fan of The Racer. Without it, The Beast would not likely exist, and I would love to see The Racer restored to its red, white, blue, smooth, racing, and backwards glory.
The Racer absolutely helped the public fall in love with wooden coasters again. It was "just" a bigger version of what riders were familiar with (Shooting Star).
But The Beast defined how a coaster could be huge, "epic", and have a personality. A story. An immersive experience before, during, and after.
Much of this is due to the hidden setting that had to be ridden to be known, and even the logo. Just look at this logo. It looks like a poster for a great horror movie. Riding The Beast, especially at night, was like experiencing that movie.
We are so lucky to have both Beast and Racer in one park!