Matt: My bubble is pretty big, it would take a lot more than that to burst it.
But thanks for trying.
Don:
There are different ways to define "best" depending on your tastes. I think Crystal Downs is probably the fiercest opening green in golf, especially coming at the end of a long par-4 that often plays into the wind. That's why I brought it up even though it didn't fit Matt's defintion. If you miss the green anywhere but short and left of center, it's a good result just to get your next shot to stay on the green anywhere, and then you've still got a difficult two-putt for bogey.
Pat Mucci referenced the first green at National and it's certainly an eye-opener; with certain hole locations it may be the most severe opening green in golf. But you are going to be about 150 yards closer to it with your tee shot than at Crystal Downs. We'll have to get Patrick to Crystal Downs someday to see what he thinks of their relative merits, since Matt won't comment on non-championship greens.
I'll have to think through some of the other possibilities. The first green at Prairie Dunes is not a good place to be above the hole, as I recall. And the first green at Pine Valley is really not a good place to miss to either side.