Easy for me - Pacific Dunes about a three months after it opened. It was a euphonious event.
Dan, I am intrigued by the idea of a (typically) mostly visual experience being euphonious. Crashing of waves? Crunching of spikes on gravel? Look fwd to more on this.
To me, Pacific Dunes was a lot more than the visual experience of being by the Pacific. But, its proximity sure adds to the experience.
Playing PD was probably the first time I really "got" what golf course architecture was all about. I could see how the flow of the holes added to the sport. The cut of the bunkers, the firm conditions. The way wind was as much, if not more, of the course's design than trees on other places I played.
Ironically, I had played Bandon Dunes about 3 years earler. I love BD, but for me it was PD that was that moment where you just go "wow".
And I know when it happened too. The stretch from 9 thru 13 really struck a chord with me. I don't need to review the holes here - Ran did a much better job on his reiew - but they just hit me emotionally. I also remember sitting on a bench for about 10 minutes up on the back tee on #17 looking over the property at about 7:30PM thinking it just doesn't get better than this.
The cool thing about PD was how I started looking for character in a golf course where before I'd been mainly concerned about conditioning and playability. Fortunately, character manifests itself in many ways - whether it's the cunning genius of Pine Valley, the sublime greatness of Merion East, or the wonderful Journey I experience every time I tee it up at my home club, which is chock-full of really wonderful architecture.