I’m still going to say Phil Scott. There’s being a popular incumbent, then there’s winning one of the most Democratic states in the country by more than the Democratic nominee did in the previous election… as a Republican. Imagine a Democrat winning by more than 43 in Wyoming (I know, this almost happened in 2006.)
Charlie Baker 2018 and Mike Beebe 2010 are good analogies for this.
The more interesting question is who might be the next one of these (other than Phil Scott himself, and also Mark Gordon, whose landslide has attracted strangely little notice).
Burgum or Cox maybe for Rs, not sure for Ds. Maybe Shapiro, if the R candidate in 2026 comes even close to as bad as Mastriano was (which is an achievement in itself). The dreamer in me says Beshear - and it absolutely would be him just a decade ago - but polarization is just too high now, so much so that there's no guarantee he'll even win at all (as LA-GOV 2019 demonstrated).