Rob, my thoughts on several places:
Union Square Cafe is not what it once was. IMO, it has grown comfortably into Restaurant middle age and DM's kitchen is not nearly as inventive or willing to take risk as it once was.
Ditto for Montrachet. It's a really beautiful room. But, I liken its menu to that of Charlie Trotter's here. It's very good. But, it has been surpassed by a newer, fresher style of cooking in that neighborhood.
Grammercy Tavern, on the other hand, has been consistently good for 7 or 8 years now. My last visit was about six months ago and everything there, from service to food, was spot on.
Nobu. Yes. Yes. yes.
I haven't eaten at David Burke and Donatella. But, I can tell you that in its prime, Park Avenue Cafe, with Burke in the kitchen, was a spectacular place.
Ben Benson's is a great steakhouse. As a matter of fact, when I worked in midtown, it was my steakhouse of choice over Gallaghers and Sparks. But, you live in a town with steakhouses every bit as good as Bensons. For that reason, I would avoid it.