Those courses are all so good.
Shinnecock would have to be number one for me, followed by National and then Friars.
That being said, if I would take National and Friars both 7-3 over Shinnecock.
Shinnecock is just so damn difficult. But, if it's just one trip I'd say it has to be first.
It's hard to imagine going wrong no matter what you play in Long Island.
I guess if you would want an order for your first time, based on the courses you listed, I would go Sebonack (which I haven't played), Shinnecock, Friars, and National. The finish at Friars and National make you feel like there is nowhere else you would rather be on the entire planet. Though Shinnecock's is just as good, I would finish at Friars and National because you at least have a decent chance to score well while at Shinnecock you're pretty much screwed unless you hit every shot perfectly.