After all the talk of Merion East, I'd love to go back and play it on opening day, exhaustively documenting each hole for posterity !
That said, I'd also go for playing St. Andrews in, say, 1600. Folks were allowed to play, the rabbits hadn't taken over, and after a few rounds I could head down to London and catch the new play Hamlet at the Globe and perhaps get a glimpse of Elizabeth I.
It's not ALL about golf, after all.