Thinking about the state that will be most emblematic of each presidential election
2020: Gotta be GA
2016: WI I think?
2012: OH
2008: This one's tough, IN? NC? VA?
2004: OH again
2000: FL
1996 & before: no idea, maybe watch old election coverage & see if they focus on any state?

As I think about it more, remembering old coverage that I watched, I think 2008 has to be VA. It was such a big swing from 2004, & it had alot of media attention focused on it after the barnburner 2006 Senate Race Webb won, then the 2008 Senate Race dems flipped that one too.

As people have pointed out, "most emblematic" could be thought of as "which state best represented the trends in the broader electorate". My conception was more of "which state featured most in the post-election narrative, will be most remembered in reference to that election."