"King's Row" is an expression that means everything is going really well as much as it is a way of saying you, the speaker, appreciate the other person whom you are addressing.

It is not a reference to the 1942 movie directed by Sam Wood that featured Ronald Regan. Ann Sheridan, and Robert Cummings.

It has originated among snowboarders, skiers, and locals along the California/Nevada border in the Tahoe Basin.